Compare my products with my rival's

Hi guys, I hope you can help me with my problem. I’m not sure if this is possible or if it can be solved using OpenAI models.

The problem:
I have a client who has an online store with a high number of products. These products belong to various categories and have technical specifications, model, brand, etc. They also have a price and available units (stock). On the other hand, I have scraped data from several rival websites, which have similar products. For these rival products, I have little more than the name, price, and some specifications.
The client wants to compare prices of rival products with their own products in an automated way to determine if their prices are competitive.

My questions:
Is it possible to achieve this with current OpenAI models? Given the large number of products from the client and an even larger number of products from rivals, it’s impossible for me to generate examples for training.
Could a model be trained solely with the list of products from my client and, without any examples, be able to match products from rival websites with client’s products?
Would this be considered fine-tuning, or would I be forced to input the entire list of products into the prompt?

I hope you can help me; I’m new to this wonderful world of artificial intelligence.
Thank you.