Overall, your GUI is actually nicely designed. I personally like the background on the second screenshot. Here’s some small suggestions to improve it:
I made the Shop Name text bigger, which gives the GUI a more full look.
I moved the Current Money tab to the top, near the Shop Name.
I wasn’t sure what the Money Leaderboard was for, so I removed it. Maybe it could be combined with the Players tab, as it already has a money aspect to it. (I’m not sure if that’s important to your game though)
I redid the Players tab to have the names near the left, which removes some clutter.
I also removed the white outline to give the GUI a cleaner look.
Sounds good! I’m curious about how it’ll turn out in the end. I’ll give some extra feedback on the third version if there’s anything that could be improved.