Well, it'll be over your budget a little bit. But if you're the adventurous type, I wholeheartedly recommend looking for a used Line 6 Helix LT and a pair of cheap powered PA/FRFR speakers. The LT has the exact same processors and modeling as the Rack and Floor versions, but doesn't have the extra ins & outs that the Floor and Rack have. I've havd a Helix Rack for over a year and still love it. It has quite a few amps, gobs of effects, both of which are added to here and there by Line 6 (the next update is supposed to have 7 of each), and it accepts 3rd party impulse responses. It's good enough that I've given up on my amp building aspirations, and am seriously considering selling my tube amps. Modeling is the way of the future. Quite a few bands have already ditched their tube amps. Bands like Metallica, Black Stone Cherry, Garbage, and quite a few others. And if you want a new one, Zzounds.com and AmericanMusical.com both offer no interest payments (they accept lousy credit), or if you have good credit, Sweetwater does the same but spreads out the payments more.
Also, it does more than just guitar. Bass, vocals, keys, whatever, it'll do it. It's insanely flexible.
But if you want something more traditional, the modeling amps mentioned above are pretty decent. But if you want tubes and are just going to play at home, you can find used Blackstar HT5 heads for around $250. Combos aren't much more. For a cab, I'd go with a used Mesa Rectifier 2x12. I have 3 of them and tonewise I like them just as well as my 4x12s. I see them go used anywhere between $300-550. But you want a 4x12, you can also pick up a used Marshall 1960 for $300-600, or a Mesa Rectifier 4x12 for $500-600.
And for a dirtbox to put in front of a tube amp, I recommend a MXR Wylde Overdrive.
ETA: You can also find various used Mesa and Marshall all tube combos in your price range. The only ones I'd stay away from would be the Marshall Haze and MA lines.
Some Reverb.com searches:
https://reverb.com/marketplace/amps?query=mesa+combo&sort=price%7Casc
https://reverb.com/marketplace/amps?query=marshall%20tube%20combo&sort=price%7Casc&page=