I'm trying to search through the user shops for items but keep finding items that are "display only". Is there a way to remove non-purchasable items from the search results?

are you sure the dropdown is set to shops and not galleries?

[edit] oh wait, do you mean when you're actually IN a user's shop? that's a known bug; search results within a shop will always show as being display only, despite the items actually being priced. you'll have to view the shop without searching, then navigate to the page that item would be on (should be sorted alphabetically) to buy from shop view. items viewed from the shop search should appear normally, though.