Well gas is good for cutting, brazing, and silver soldering, but on thin steel it distorts from the heat. IMHO, perhaps a like of skill? MIG around the house and not used much, wire gets rusty, jams cable, and you need gas unless you use fluxcore wire. Plus the cheaper ones I've tried suck. I hate MIG!! When fab shops first got them, Some assholes thought you never needed a break. 40 lbs. of wire is a long time between breaks.
TIG I'm not good at, because I'm nervous, shaky. I can build SS beltbuckles, rings and such. But would never call myself a TIG welder.
Tig you can weld more alloys, better with, but you might need to change the gas, rods. TIG DC won't weld aluminum, TMK.
Around here the companys get a better price on bottle refills than me. Some folks come around for work, I just tell them, sorrry no gas. SOBs to cheap to pay. Sorry for TMI
BTW AC welding current will bite your butt, big time. DC you just taste and turn your fingernails blue.