Welder purchase advice please

Hello all. I was hoping to get some advice on buying a new welder. I
already have a gas rig and a small Miller 135 MIG. I wanted to start
playing with TIG and have been looking for a unit to buy. I'm a
hobbyist and won't be making a living with the welder. However, I don't
want to buy junk.
I was looking at the new, lower cost units from Miller, Lincoln and
Hobart. They all seem to have something for around $1300 and a better
model for around $2000. I want AC for aluminum and HF for arc starting.
I checked my local paper and found someone selling an older Miller 330
a/bp with a Bernard water cooling unit for $1000. It is from a closed
manufacturing business, and the guy says that it works like new.
I was hoping to get some advice from those in the group who are much
more familiar with welding equipment than I am. Any advice will be
greatly appreciated.
Regards,
Mike M.