I am trying to find the cheapest welder that I can that will work for a while and that I can learn on.
My experience has been that some of the cheapest welders are the hardest to learn on. The stuff at HF compared to something like Miller or Lincoln really goes back to the adage about "you get what you pay for."
I was able to pick up my MM250X used for $900. I had just about been ready to spring for a new MM210 which would have run me about $1300.
Again, take the classes first. That will give you a much better idea of what you are looking for and the ability to judge whether you are getting a good deal on something.