Here's some "cheaper" tubes amps
http://www.norh.com/

http://www.enjoythemusic.com/magazine/archives/

2Xspd also recommended some great value tube amps in a previous thread a while back. Do a search you should find it.

With these you very well may not have to build your own. Unless ofcourse that's part of the fun for you.

Cheers, Jag