Ideally under the 1K mark.

are you welding aluminium?

Have you tried on http://www.mig-welding.co.uk/forum, lots of useful stuff.

http://www.velocipedesalon.com/forum/f10/tig-welder-advice-26919.html

If you are looking for new then R-Tech seem to be a good price:
http://singletrackworld.com/forum/topic/aluminium-tig-welder

But if you are not welding aluminium then you can easily get a DC machine, secondhand, for under £1000. Esab, Cebora, Lincoln, Cemont, Fornius, Migatronic, Kemppi, etc are all good.

Almost all companies make good Tig welders, although Cobel have made some junk.

The price of a foot control pedal can be surprisingly high. Have a look at the cost of a Kemppi or Cebora foot pedal. Even a cheap welder like GYS has a foot pedal that is over £200.

But you can weld a bike frame without a footpedal. You can also weld a frame without pulse but it does get easier with pulse and a pedal.

A lightweight torch WP9 is easier to use and maneuver than some of the heavier torches.

http://www.weldingtipsandtricks.com/tig-welding-bike.html

I brought a r-tech dc digital with a foot pedal
It’s Dc so no aluminium but it’ll do steel and Ti as well as TIG brazing too.
It also has a pulse setting which is usefull on stainless.
Next purchase will be a water cooled torch and I’ll build or buy a cooler for it