For those not comfortable under the hood, there's a lot to be said for new and a warranty card. I haven't played any of the current tube-driven, price-competitive makes; Crate, Peavey, Carvin or, for that matter, Fender.
'Worth'; the monkey and the football. If you pay mid $400s for it and the retailer gets his cut, then the retailer paid $250-$300 for it; said another way, it's a $300 amp; 2XEL84, 12" speaker, reverb - a pretty nice formula - or, about the same money as a 40 year-old Silvertone 1482; add the $$ necessary to get the Sivertone stabilized (power supply, speaker, bits and pieces) and you have rough financial equivalence. While the old stuff can exude charm and generally bring what you paid for it, it cannot exude a warranty card no matter how hard it tries.
At the end of the day, it will cost what a stabilized 1482 costs (BTW no reverb); without A/B'ing, no way to tell which is the more pleasing to you or more in synch with the T5. 15 watts is more than enough and I'd have to say that the EL84 is one of the more versatile output tubes out there; well-supported w/ history back to the 60s.