The problem Seller-Safe Paymaster Escrow solves

Here's a scenario -

You own a bunch of NFTs, some worth $100 or some really nice ones upto $1000. The space is booming like crazy and you find yourselves making crazy markups, and are just getting ready to flip your NFT for a nice 50% profit. Sounds awesome right? Except, you just forgot to take gas fee into account, again. And now suddenly the 50% profit you were making on your 100-200$ NFT is simply gone (well, the miners thank you).
Additionally, if you're one of those who recently got into crypto (I'd image tons of new artists coming in right now), there's a very high change you don't keep extra Eth lying around, and boom now you first need to figure out where to acquire more Eth from to pay for "transporting" your art. Suddenly the 50% profit doesn't seem worth the trouble anymore does it?

It's no secret that the gas fee on the ethereum chain makes it pretty much unusable for the normal people. A 50% flip would be considered awesome in the normal world for small time art traders, and even those who create their small art peices and sell it at a 50% markup on their supplies costs'. Also, if we think about it, a lot of regular artists charge their buyers for the shipping costs, so why can't we do the same here?

So that's what we solve.
We initiate a contractual agreement betweent he buyer and seller of an NFT, where the buyer places money in escrow for the cost and the estimated gas fee (can't be detererministic, ofc), and using GSN's paymaster approach, we then transfer out the NFT to the buyer, without the trasnfer actually costing the seller any additional gas fee.

Challenges I ran into

This was pretty much the very first project I ever had to build on web3 on my own, and that definitely took a lot of time in udnerstanding how eveything just fit together.
From setting up the dev environment to working and understanding paymasters, everything was pretty much a challenge!