collectible sale app ideas

I'm a year 2 graphic design student, and in my UI/UX design class we are making an app. I decided to make my app an online marketplace specifically for collectors, it'll have filters for what type of collectible it is, down to brand, or if they'll accept trades. I really wanna make this a thing and I'm wondering how much interest there can be in this kind of app that by and for collectors. It may have a discogs-esque pricing guide to show average prices for certain objects to prevent scalping.