Lots of questions and ZZR has mentioned the main one which is what's its primary use.
If it's just for ferritic type steels 1000-1500 buys top gear with entry level machines such as Miller Sth, ewm pico, esab caddy 1500 etc etc. If you want to weld aluminium and it's alloys then the price rockets and 1500 doesn't touch those brands if buying new. In this case for that budget my personal suggestion would be the 202 offerings from either thermal arc or parweld.
Aluminium can be an expensive hobby depending on how seriously you want to take it.
Consider seriously watercooling. Ac welding has part of the output current going into the electrode which is harsh on gas cooled torches and quickly knackers them once you start getting into triple digits on the amps.
Most alumium Tig welders will say get a foot pedal. I say it's very handy to have one and will make life easier as you can control your heat on the fly. Not essential mind and in some cases not always possible to use one but again a big cost attached to the machine.
If I was you Id buy the thermal arc 202 with foot pedal package. Then as my first project Id build myself a water cooler then when done treat myself to a lovely wp20 water cooled Tig torch. Your budget should cover most of that whole outlay if you shop smart. I built my own cooler so I can help if you need it.
United welding are good for welding kit and certainly one of the better priced.
Don't dismiss the parweld 202 ACDC it's identical to the thermal arc and @Tom Orrow L deals with them so can give you all the info you need on them and there accessories.
Regarding water cooling if you want to buy one they start at 3-400. If you want to build one then I'm happy to throw a few suggestions.