Maybe this is a dumb question... But I can't buy anything because, apparently I own over 100 items (but I don't even have 10 items in my inventory..) Do items in your shop count? (Because I have a lot of items in my store).

If you have multiples of any item, they all count. Items in your shop don't.

Do you have multiples of any of the items?

....-facepalm- Whoops, now I know the problem (I have too many Vesnali coins. xD ) Thank you. c:

during Vesnali it's helpful to have Esther's turn-in page open in a separate tab or window and every so often refreshing on it until you get all you want from her shop. This clears all the dang Vesnali Coins from your Inventory that interfere with normal gameplay.