I have a Lincoln 110V MIG Pak which comes equipped for flux core but can easily be converted for gas and aluminum. I got it at Home Depot a few years ago for ~$350.00, it's been replaced by the Weld Pak 125 which is $419.00 according to the Home Depot website. People have told me a thousand times it's a useless toy but so far it's done everything I've asked of it, including building roll cages from .095 wall tubing. When I did the first one, I made some test welds and cut them open to look for penetration, all was well. FWIW, a buddy has a nice 220v Miller with gas, auto set and all the bells and whistles but he and I can both lay better welds with my Lincoln.
It does need a lot of 110V power, I ran 20 amp service for that reason. I also use my head and try to limit myself to .120 wall stuff in stressed applications even though it's capable of .250. The thickest I have welded is 3/8" plate for a steering box bracket on a tractor; technique is most important on that. It's necessary to bevel both sides then fill it in. But on something that thick, yeah you'd be better off with 220V. I made a set of brake caliper brackets from 3/8" also, I tacked it with my machine and then took it to a local pro for completion just to make sure.
Stay away from the Harbor Freight/Campbell Hausfeld cheapies. Along with limited usefulness (hard to convert to gas, for instance) their worst feature is the wire is 'live' as soon as you flip the switch on. That can be very bad when you are, say, under a car getting ready to weld and inadvertently brush against something like the fuel tank.
The Lincolns, Millers etc do not power the wire until you squeeze the trigger.