What set(s) should I get next?

[Username]

I'd go MMV and Battle at the Pass. If I had the cash though, I would get the Giant Chess set.

[Ye Olde Republic]

IIRC, there isn't anything in the blacksmith shop to justify it being $200. If it's something you think you want you'd be well off buying or downloading the instructions and just buying the parts for it for much less than $200. It's well worth getting though, it's a really nice house.