I had a Miller Bobcat that I ran for at least 15 years, and it was an excellent machine. I eventually ended up having to replace the motor because it was burning more oil than gas, but it had in excess of 3000 hours on it! After I replaced the motor, I started having other things go bad, and it just started nickle and diming me to death. So, recently, I bought a new Miller Trailblazer. I've always had Miller stuff and have been very pleased with it. Like anything though, when it's used up, it's all over.
Just be aware that even when a machine looks like new, as my old Miller did, it can still have it's problems. When you have to work on it for 8 hours to get it to run for 3, it isn't a very good value! I'm a firm believer in "you get what you pay for".
Hope you find something to suit your needs. Lrt us all know what you end up doing!
Chaikwa.