Started selling on TCGPlayer. Taxes almost make it not worth it compared to selling to shop.

I recently started selling on TCGPlayer and was curious how people handle taxes for selling on the platform. I come out ahead selling minus fees and cost to ship but when I factor in my tax rate I'm basically better off getting 70% selling to the shop. Is there a way to optimize taxes selling cards to make it more profitable?

Edit: I'm selling excess cards from packs I open so I'm not sure the best way to assign cost to them. Some I bought from my LCS or some I got from winning by playing the game.