what is the least expensive welder i can get away with ?

I agree with lowbudget and stay away from off brands. Lincoln, Hobart (Made and owned by Lincoln), and Miller is the way to go. Another thing to watch for is if you buy lets say a lincoln at big box store H@me D&pot there is a difference between those welders compared to ones that you would buy at local welding supply place. It is minimal difference, but big box is a step down. Also try and return welder to big box for repair if needed and you probably get the clueless face or hear sorry can't help you. You are better off just dealing with welding supply cuz you bought it there they will make more of an effort to help you out.