They've been running a 25% off anything coupon but according to emails they've sent, it expired yesterday.
I bought a big *** long reach jack with it. Those are usually excluded from coupons too.
The MIG 140 welder will work fine for steel, and instead of spending money on a spool gun for aluminum, I suggest spending the money to pay someone that knows how to weld aluminum to do it instead. Then save up for a TIG welder.