Snap On MW120 MIG Welder

My first mig on which I'd gotten from the Mac guy, I found out was the same as the first "homeowner grade" mig I used to see in the ad section of popular mechanics magazine for something like $129. I didn't know that at the time I bought it.
The Mac man that is gotten that one from, had made such a huge deal about it coming with the "extra cost" gas bottle kit. That welder was actually made by astro as a used, "repo special" I paid something like $650 for it, back around 1991/92ish.

. When I first got my current job 10 years ago, the 1st location I worked at for them had one as their "shop welder". It did exhaust work ok, in it's highest setting but luckily I didn't need it much.

My 2nd one was something by century, found at a garage sale a Grandpa had bought his grandsons after he found out they were in "welding class" at the local high school. He thought he was doing something great for them but they only ever used it like twice since new and lost interest. That was about 1994ish.
Had to do some utility trailer work, (small repairs each time on different trailers) and burnt out one of those welders on each trailer job...

When I bought my miller 185 I was starting on a trailer I built from scratch. I have since built a 2nd one from scratch with that same miller 185 and a whole lot more in the years since and never an issue. I'm about to get into a pretty big D150 bodywork project and Im wondering if this miller might be "too" big. I've never tried to run anything smaller than 0.030 in this machine. Usually since I've had it, as it is now, it's loaded with 0.035. I can't believe what the cost of mig wire has done and most I find is Chinese to boot.
I have a buddy who's a retired welding teacher, who told me at one time "not to buy wire, he has more than he'll ever use" now that he's retired, but I know some of what he has is pretty old now.... And I've had plenty of problems over the years caused by running old wire.