The problem you're going to encounter with 'small' tube amps is the fact that companies don't sell a lot of them, so they have a much smaller number of units to spread the production costs over. So builders try to cut costs by reducing the number of features in the preamp. Also, low-power parts and components cost about the same as their high-power counterparts. So people tend to avoid them, preferring to get 'more bang for the buck' with big amps. Which means that production runs are small, giving fewer units to spread the costs over.....

You end up with boutique amps like the 3 Watt Carr 'Raleigh' which retails for US$1250, or the 15 Watt Gretsch G6156, for US$2950! Nice amps, for sure, but the market is limited.

You could search around for clone versions of the old Fender Champ. The Blues Junior might be just what you're looking for. Maybe an Epiphone Valve Junior. I've seen them priced as low as US$160. Or look at the 5 Watt Gretsch G5222 Electromatic, retailing at US$195.

These are very basic amps, but they can put you in touch with the concept of 'Tone Is In The Hands' because there aren't a lot of controls to mess around with.

One amp I haven't seen in person, but I'd like to try out, is the Egnator Tourmaster 4212. It's a 2x12 combo amp with a full-function 4 channel preamp. The output is adjustable to produce 100, 50, 25, 20, or 10 Watts. At US$1599, it isn't cheap, but it may represent the way of the future.

Bear in mind that even a 5 Watt amp is still going to be way too loud to crank up in an apartment. But there aren't many clubs that will let you run a 100 Watt full stack anymore, either. A lot of places insist on having everybody run at low levels with the speakers miced into the house PA system. Therein lies a whole 'nother set of issues, but we'll leave that for another thread.