I'll let trade fortress speak for himself, but he's done a great job addressing issues I brought up. There have been errors, but he has worked to fix them. 27BTC for a site is pretty inexpensive I must say, though I agree it's not cheap if it doesn't work.
Maybe try speaking with him more and you guys can maybe find an amicable solution to your problem. I've been working with him for awhile and the site is actually quite complicated:
www.terrawallet.com and I've been happy so far.
I hadn't thought about future code maintenance, perhaps I will speak with him about this, but I personally can't support a scammer tag at this point. I would say to try giving him another chance- Debugging is a long and hard process something that I think both sides need to dedicate a lot of time to.