Back in August of 2025, the Youtuber Justin Resells, who I subscribe to, released a video with instructions on how to use Chat-GPT to build an app to aid in deciding whether or not to buy an item to flip.
Using the instructions provided does create a great app, however, it does require a paid plan using that service ($20 per month).
As a smaller seller (fatwalletrefugee), I don’t have the budget to afford this additional cost of business. So, instead I have used Google Gemini to replicate the functions of Justin’s original app.
Here is a structured, reusable prompt based exactly on the workflow Justin built in the video.
Since you are using a standard chat window rather than building a standalone Custom GPT, this prompt is designed as a “System Persona” introduction. You only need to paste this at the very beginning of a new chat session to turn this assistant into your personal sourcing tool.
Copy & Paste this Prompt:
Plaintext
You are now "The Sourcer," a specialized AI assistant for eBay resellers. Whenever I upload an image of an item, your job is to identify it and provide a concise analysis with exactly four distinct sections. Do not show your mathematical work; provide only the direct answers.
Format your response exactly like this:
### 1. Optimized eBay Title
[Provide a search-engine-optimized, keyword-rich title under 80 characters, prioritizing brand, model, material, era, and key descriptive features.]
### 2. Estimated Value
* **New / New Old Stock (NOS):** $[Estimated active/sold open-web price]
*(Note: I understand these are rough open-web estimates and not live eBay API data.)*
### 3. Max Purchase Price (Target 2x ROI)
* **If New:** Do not pay more than $[Calculate: (New Value * 0.85) / 2]
* **If Used:** Do not pay more than $[Calculate: (Used Value * 0.85) / 2]
*(This limits my buy cost to half of the expected payout after factoring in a 15% eBay fee. Ignore shipping costs for this estimate.)*
### 4. Market Research Keywords
* **Search Phrase:** [Provide one short, natural 3-5 word keyword phrase optimized for finding this exact item on eBay]
Please confirm you understand by replying with: "The Sourcer is active. Upload your first item photo when ready."
How to use it in the field:
Open a fresh chat on your phone and paste the text above.
Once the AI responds confirming it’s ready, simply use your phone’s camera to upload a photo of an item you find at a thrift store, garage sale, or flea market.
To do the final step of Justin’s workflow (checking the live active and sold listings), just copy the phrase generated in Section 4 and paste it directly into your eBay mobile app search bar.
I find it slightly annoying when I search for a style code and Google insists there are no results related to my search. This happens often enough that a post like this has become necessary.
This post is mostly for my own records, but the data may prove useful for others, so it’s not being written on a post-it note.
Page Updates
I’m adding more information that is adjacent to the list.
April 14th: Added link to Bandeau.fyi for swimwear.
March 11th: Added section for the Target brand Auden. Expanded the garment types to include Pants, Jeans, Shorts, Skirts, and Skorts.
Helpful tidbits for when I am out sourcing and don’t know what something is or how to describe an item for a listing.
The distinction between men’s and women’s for the Under Armour Velocity series appears to be the necklines. Men’s features a crew neck while Women’s have a V-neck.
The firm selling the Arcade belts has an official eBay account, and all of the pictures I found online were from the manufacturer.
It is generally advised not to use the brand’s photos in your listing; take your own photos to avoid getting flagged for copyright or trademark issues.
I have received a VeRO take-down in the past from Samsung for misuse of images and trademarks.
If you need an image and can’t take your own, you can use any of the ones included in this post.
RN Numbers
The FTC maintains the RN database, it will tell you the importer/manufacturer info. Only really useful if you don’t Have a visible brand on a textile item. — @Jlbeaver2
Amazon LPN Codes
An LPN Label is a pre-printed label with a unique number that only fits one pallet or one box. At Amazon warehouses, any item marked “non-deliverable” is affixed with an LPN sticker regardless of whether the item is new or a return.
When reselling, it is important that we check the product’s condition, because often the LPN-affixed packages may have been used by the customer. You’ll encounter this more often with clothing items than with things like hardware or office supplies.
There are distinct patterns in the leading letters of the codes, and some codes have been determined.
Code
Status
LPN N
New
LPN RR
Returned
LPN PM
?
Women’s Garment Types and Styles
Outerwear
Women’s Tops
Blouses, tanks, t-shirts, halter, crop tops, and more.
I’ve noticed an odd trend of listing tank tops and camisoles as vests, which is inaccurate. A vest is a piece of clothing, like a jacket without sleeves, that is worn over other clothes for warmth or protection.
Camisole
Camisoles can be both innerwear and outerwear; their function depends on the material, design, and how they are styled. Traditionally, camisoles are worn as an undergarment (innerwear) for coverage or layering under sheer tops and blazers.
However, with their variety of colors, designs, and fabrics, camisoles can also be worn as a standalone top (outerwear) for casual wear, sleepwear, or even dressy occasions.
Bottoms
Pants and Jeans
Wide-leg trousers and 90s-inspired denim are a dominant trend. These have evolved into a wardrobe staple, often featuring ultra-high rises, pleat details, and partially elasticated waistbands for a “fluid and flawless” look.
Shorts, Skirts, and Skorts
Denim skorts and high-waisted shorts are particularly prominent, often featuring vintage-inspired fits like the “mom” short.
Undergarments
Bras
The purpose of a bra is to provide comfort, support, and shape to the breasts, though the specific reason for wearing one varies widely among individuals.
For those with larger breasts, a well-fitted bra supports the weight of the breasts, which can prevent pain in the shoulders, back, and neck.
Bras provide a layer of coverage, preventing nipples from showing through clothing, which is important for modesty or to conform to social expectations in certain settings.
Bralette
A bralette is a lightweight, wire-free, and often unpadded undergarment designed for comfort and a natural look, providing soft support without the structure of a traditional bra.
Bralettes are versatile, serving as everyday bras, undershirts, or even outerwear, and are available in various materials like lace, mesh, and cotton, with options for removable padding and different styles such as seamless, strapless, and racerback.
Young Adult Bras
Prioritizes comfort, proper fit, and age-appropriate style with adjustable features like straps and bands.
Featuring soft, breathable fabrics and wire-free designs to accommodate growth and prevent irritation. Comfortable bralettes for everyday wear or supportive sports bras for an active lifestyle.
Bandeau
The Bandeau’s functionality makes it an excellent choice for everyday use.
It is commonly seen as streetwear, in swimsuits, and as underwear.
Target Clothing Style Codes
The following are items I have had to look up when listing items on eBay.
I think Target is generally good at keeping sold-out listings active on its site for some time after the season ends. This makes it easier to find all the specifics of an item we want to resell.
I’ve included links to my eBay listings so you can see photos. I don’t have an unlimited amount of space on-site for photos, so I am prioritizing the mobile game wikis.
The PID# relates to Targets’ name for the specific color of the garment and will often still be active after the season has passed.
FatWallet Refugee 