"Sometimes when we weld alum with high frequency sometimes the frequence fluctuates a little bit,besides that everything works great!"
When I wrote back asking for more details about this he said he would talk to his welding techs on Monday and get back to me. He also said he had another buyer if I wanted to change my mind about the purchase so no need to worry.
What should I do? Does that sound like a component is failing or is it something I can live with indefinitely? I have zero actual experience with TIG welders. I can't even afford to pay what is typically being asked for these used machines. Forget buying new! This one was affordable. If it's 99% functional and is not doomed to fail completely, I can live with it. Or, repair it when I can afford to later.