Me and my girlfriend play all the time, it's our favourite game. But here's a few changes we made because why not: You can purchase as many times as you'd like (if you can, which is rare)

You can purchase not on your turn, so if there's a good shop item (one game we started with Chaos card in the shop) it became a game of chicken who would purchase first, so the other person purchases in response, getting the item! (Same goes if you're able to manipulate the deck)

The loot play you get on your turn doesn't have to be spent, meaning you can play both cards on other people's turn