Hey Marty

Here are a couple of links you might also find helpful which I used in the course of bringing myself up to speed.

The first, Eurotube will give you some idea of maintenance required/do-it-yourself costs involved with a tube amp (vs digital which is nada).

This one (in two parts) explains how it all works on the inside. Don't need to know this stuff to play which might be too technical for the need or interest of many, but it's gold for the inquiring mind that just 'needs to know'.

Lastly, a few suggestions from the too many to choose from.

[br]For a home studio/practise tube amp, I like this one which sits in your preferred price range -specs, price & reviews here. Alternatively for a little more but still with your budget, one of these, the 6L6 (demo) being my particular favourite. Or, choose a Studio 10 in your own preferred tube flavour, 6L6, EL34 or KT88.

Brand bias disclaimer: I own and play a Blackstar Artist Blonde 30W 6L6 2x12" combo amongst others, but I'm not blind to other brands also owning two Fender amps one of which is a 2x12" solid state combo I'd buy again. Any bias is preference for the 'ambitious and hungry for recognition new boy on the block' performance:value ratio of Blackstar amps.