Dont get one from bunnings or supercrap, they are shit!
The gasless ones at supercheap are about $400 I think, a complete ripoff.
I got my Uni-Mig 120 off ebay brand new for $400 they retail for about $600, they're a great little mig by a well known company, but made in italy (fairly generic, specced by Uni-mig but uses off the shelf parts Im guessing)
I did a fair bit of research and I really think its the best thing out there for the money.
At first I bought a small spool of flux-core (gasless) which worked OK on the beetle, welded in about 10 panels, then went to gas which is much better.
If you plan on using the welder a lot (which you will end up welding everything in sight!) it is more economical to go to gas as flux-core costs about 3 times as much as solid (gas) wire.
The Uni-mig came set-up for gas and even includes a regulator which I have seen in a local welding shop for $90! The cheap ones are gasless only and not able to use gas, ever.
The wire drive on the uni-mig is much better than the bunnings/mitre 10/supercheap etc ones and the gun is much better quality,
Also most welding shops will stock spare parts for the uni-mig which is important, you may have a lot of trouble finding spares for the cheaper ones.
Also service is great, rang them up with a problem with a gas fitting and they are sending me a new peice free of charge.
another user on here has one and they are very happy as well, they are not the best welder but for the money you will not find better.
Go to ebay and search for "mig" or "Unimig" and there is normally always one of these welders on there for auction, tho there isnt at the minute.
http://cgi.ebay.com.au/MIG-WELDER-120-amp-UNIMIG-PANTHER-120-WELDING-TOOL_W0QQitemZ4385973270
www.UniMig.com.au
If you want to see some more pics give us a buzz, have a few including some of the inside components.