I have a Lincoln Square Wave 255 I bought it new in 1997 for about $2600 at the time. I added a water cooled Tweco gun about $175 a Lincoln foot pedal about $130 and a Lincoln water cooler ~$500 . I got this right before the inverter type welders took hold. I wish I had one of the inverter type because the SW255 is big and heavy not making it too portable.
This unit works very well. I mainly use it for welding Bronze together. Sometimes Aluminum and steel.
For my every day Aluminum welding, I have two Lincoln InverTec V-350 Pro with Python push pull mig guns. These get pretty pricey I think the last one I bought was around $8000 for the whole setup.
Here's the Tig machine that I have:
http://www.ebay.com/itm/Lincoln-Squa...kAAOSw34FVCHZU
This is the one I should have bought but I didn't have enough $$ at the time.
The cooler and foot pedal on the top in the picture are the same as mine.
http://www.ebay.com/itm/Lincoln-Square-Wave-350-TIG-/291673416210?hash=item43e9172212:g
u0AAOSwKIpWDmX k
You may find a nice used one at HGR Industrial Surplus
hgrinc.com