Go to your local welding supply place and tell them what you're wanting to weld and what process you'd like to use. See if they have any used welder available or know of anybody looking to up grade. You can also keep an eye out for one on Craigslist.
If you want to mig weld Lincoln or miller makes a nice 180 mig machine, 220 volt. Lincoln also makes a Dual 180, meaning you can either plug it into 220 or 110.
For stick or DC Tig Lincoln makes a small V155 machine that's the size of a small lunch box, they're 110 or 220 volt; I know miller has a similar one just don't know the model number. Miller makes a small AC/DC Tig machine but they're $2k plus new if I remember right.
The Lincoln or miller 180 should run you $800 - $900.
I've got a Lincoln 180 & V155. I really like the Lincoln 180 for its size & being able to weld thinner metal easier. I also like the V155 b/c of its size and how easy it is to pack up.
I also have a Lincoln 185 pulse Tig/stick machine & miller 200 mig welder. The miller mig welder I bought used from our welding supply place back home for $700; its an older machine but it works good and very consistent.
Hope tat helps.
Yellowchevy