Kathy, you don't pay the transaction fee on app in person sales. You pay the payment processing fee, which is the same as squares. And, if it is a multiples, you do pay the relisting fee.
I use the sell on etsy, because I like it controlling my inventory and helping with relevancy for my multiple items. The boost in relevancy is worth the $0.20 to me.
And I am too lazy to try to do bookkeeping on more than just etsy and paypal. And I hate the paypal reader.