As for costs of tube vs solid state amps, there are some less expensive tube amps out there (up to about 100 watts or so). For efficient speakers the MiniWatt is amazing at $350ish. For more powerful amps, look at Rogue or Quicksilver. Line Magnetic may also be a good option.
For higher power with some tube sound, maybe look at hybrid designs. Vincent or Butler for example.
For higher power with some tube sound, maybe look at hybrid designs. Vincent or Butler for example.