i would go for a decent brand, CIG/BOC, Lincoln, and get the biggest Amperage one you can afford.
a mate has an older version of this, best thing is it is portable (size of a small suitcase)
Lincoln Power MIG 180C MIG Welder | eBay
this one is a basic, Gassless only mig, would be a cheapish first/learning mig for you.
NEW Dynamic Power 130Amp MIG Gasless Welder Welding Machine Tool | eBay
buying a better Mig, in years to come you will still be able to buy parts for it, if it needs repairs.
mine has only needed a new liner for the gun which was about $20, and a heap of tips for it too, @ $5 each
being a Panel Beater/Fabricator i have given my Mig quite a hard time over the last 13 years.
don't forget to buy a decent helmet,
i have a few Automatic Darkening helmets (available new now from $50)
and buy some spare Tips for your gun, a pair of pliers, and a set of Welding tips cleaners.