Yes, vintage Pokemon cards have an established market that lives primarily around eBay but also through social media sites like Instagram.

So when I say that a PSA 10 1st edition Charizard has sold for $40k, I say that because they have been multiple $40k sales and the card has not sold for less than that for 2 years now. In addition, there are many people trying to acquire one for around the $40k market price, but those who have them are asking for more.

This is just one example.

There are a few cards that don't have an established "market price" because they are so rare. The card that sold for $225,000 is one such example.

Selling Pokemon cards is certainly not my day job. I'm a teacher. Although before you tell me I should sell, I do have certain financial advantages that have come from my parents and my wife that have put me in such a position that I certainly do not need to sell. (My "$200k collection" is only a sliver of my net worth).