The cheaper 90 amp 100 dollar jobber will work on exhaust also. Itll plug in and work from an extension cord as well.
If spending a few hundred whats another hundred to buy a quality machine that will last you your lifetime?
Using flux will piss you off with leaks and ****ty looking welds.
Thats all the 100 dollar one will ever do, atleast the 170 amper says you can add gas.
Buy a used name brand setup, buy one without gas for now and save the money to be able to lay clean welds if the need arises.
I can tell you I love my Hobart i bought new. Doing dozens of exhaust mods and other odds and ends has paid for itself many times over.
