Silvertrd. If your in the market for a 250 amp tig there are several good options. The syncrowave 250 is a good machine. Upside, stable arc, lots of features for the money. Downside, heavy old transformer style machine. Also a power pig (which all traditional low frequency transformer machines are.) Another good option is the Lincoln Precision Tig 225. Upside, good value and very user friendly. Downside, heavy old transformer style machine, power pig. In my opinion, if your willing to spend around 3k, the Miller Dynasty 200DX is the best choice. Its an inverter based machine which means light weight and power efficient. It also has more features than the others, and you can move it around without the use of a crane.
Where to buy? I would go to www.Millerwelds.com
and find your local dealer/dealers. Then I would get pricing from each one I could find. Don't be afraid to tell them you are shopping around if you want your best deal. And lastly I would check with your local welding/fabrication shops. They might have a used machine at a bargain, plus I would ask their opinion of the local dealers. Most shops will tell you which dealer they recommend, might save you some grief. Personally I would stay with your local dealers vs Internet dealers. If you ever need warranty work, your purchase with your local dealer makes all the difference.