Interesting entry level would be the Black Ice FX10 or the Musical Paradise MP-301 Mk3 (both are integrated amps).
The FX10 is PP EL84 coming in @ around 12 watts for $800, or so, and the MP-301 is single ended (various output tube choices) coming in @ around 6 watts for approx. $500.
Both are well reviewed/Google them.
Once you move on either would be super for a desk top or other 2nd system (or as a gift to someone else starting out).
DeKaY