I am looking at a couple of Lincoln Electric MIG Welders. One has tapped current control and the other has continuously variable current. The tapped unit is about $100 cheaper. Is the extra $100 worth it?

Subtract the minimum current from the max and divide by the number of steps, if the answer is 17.5 or less - go for it

Does anyone have a Clarke Welder? i have see them advertised in the US and they seem to be inexpensive? Or are they just junk? Clarke 130EN Welder package

I have one of these

http://www.machinemart.co.uk/product.asp?p=010110135&r=2029&g=105

and although I have no basis for comparison I'm very pleased with it.