You dont pay gas fees when minting on Polygon. Buyer or seller. There is talk of 30 qwei fee in the future, I need to confirm this, and if this is accurate I need to find out where its charged, creation or selling. I don't mind a small fee to fight spam tbh, but I do mind if I have to drop it on creation and not transfer or selling. This would slow my giveaways on their platform. But, if sales work out, I can just raise the price by that 30 gwei charge (right now thats $0.00007857 according to nomics.com seems low tbh Id think its be more expensive in USD right now) compared to the over 300,000 (*nearly 400,000) gwei it costs to mint on the tradional OpenSea system. Thing is, I havent actually noticed OpenSea bring this up themselves. I follow them, but I could have just missed their announcement. I know they added a feature that hide unsolicated NFTs unless theyre from a verified collection.