I have checked scrow services but they either don't accept cryptos, or look sketchy or charge like crazy fees 10-20%, and there are also a lot of scams apparently via scrow fake agencies which makes just not worth it.
Where did you check escrow services? Not in this forum i guess. There is a lot of escrow providers here with an excellent reputation and i guess they also offer services for trading goods.
It will be better to offer the entire collection for sell at once .
I can't tell you how this may work but if you are honest enough, you will surely find the way here. Use board of "Goods" :
https://bitcointalk.org/index.php?board=51.0List of escrow providers in btt forum :
https://bitcointalk.org/index.php?topic=2439910.0