Yeah, you need the Shoe 👟 if you want to earn with the app.
The NFT floor price can be checked here; https://magiceden.io/marketplace/stepn
It's quite expensive for an average user at the moment because the app is still in development mode and only few are using/playing it ATM. Once the renting feature of app is finally released everyone will be able to join the game at a few $$$ and move-to-earn.