The way the DTS system works (although I haven't tried it in a while) is that if they confirm your issue is an eBay API bug, they'll refund your money. You may want to double-check that process, though, before you get started submitting your bug. They also seem to visit the forums here occasionally. Maybe wait a week or so before filing your paid ticket, as they may notice this thread.
I am also experiencing this bug. This API is a shame. I have already paid for the support, and even after reporting this bug (so as anothers i've encountered), they simply ignored me. What a wasted of money.
I am facing similar problem with conditionId = 3000 while searching for product in EBAY-IN region for Category id = 15032 (mobile). However, if I change the region to EBAY-US error goes away. Please let me know the solution Failure 10 Marketplace Error Application Invaild item condition. Search 2000 1.13.0 2015-10-16T11:08:48.570Z