I was first introduced to the Miller EconoTIG when I worked at a shop that had one.
Later, I opened up my own shop and bought one for myself. I never found any TIG welding chore that it wouldn't handle.
The place I work now has this huge Lincoln TIG setup,..ain't no tellin' what it cost. I'd guess somewhere in the $5000 range, but I've yet to find it capable of doing anything that the Miller EconoTIG can't do.
Unless you get into some very exotic application of TIG welding, the $1600 EconoTIG will do the job and do it very well.