Hi! You use the mouse wheel or controller bumpers to cycle through all the bartering options, like you do when switching inventory items. My intent was to make it easy to simultaneously tab through items while also switching between Buy and Sell. However, I definitely could have done a better job of conveying that functionality to the player. A lot of the feedback I'm getting is that it feels good once you get used to it, but it's super clunky at first. That means I need to make this system easier to understand for new players. I'll note your feedback down and make some improvements to the system in a future patch.
I really value your feedback. It's super rewarding to have notes like this that allow me to improve the game in ways I didn't even think of. As soon as the inventory gets addressed in a patch (and trust me, it WILL), I will note it in the patch notes. Worry not: patches do NOT affect your save file.
Thank you again! Share Wizzerd Quest with your friends and keep the feedback coming!