Maybe you can bet NFTs against other forum users, a lot for them has NFTs and like gambling, so, maybe if you find the right users and the right match to bet you could find a scrow who hold the NFTs while the match is going on.

The problem about betting the NFTs is the price of the NFT, the fact that I can put that NFT on a market and ask for $1 million that doesn't mean that's the real NFT cost.