Miniwatt N3 is neat with infinite driver tube rolling options(1X 12ax7) but there are so many better(than N3) choices for that kind of money from China and HongKong(Miniwatt is also from HK, in case anyone didn't notice).
I have been doing my homework in shopping for tube amps under 400 dollars for almost a year now. Sinovt 6V6 amp can be bought for $450 shipped and it has features that can be found in premium gear such as use of a tube rectifier and a power choke. It also has very decent power and output transformers and high quality circuit parts for money. There are many other chinese brands out there but parts and build quality are much better than other similar priced chinese tube electronics like Yaqin, Xiangsheng and Meng.
This one link I've found while on diyaudio forums about a place selling Xiangsheng amps for under $310 shipped available with tubes like EL84, KT66, KT88, FU50 etc. There's a thread on diyaudio forums regarding FU50 tube version and many seem to be happy with it.