I bought one in 2012 from China on ebay for about £500. the brand is Cobel which was a common name at that time but all these Chinese welders are similar inside and just badge engineered with some of the switches and knobs moved around and a different colored box- R-tech ones are too. R-tech have a good reputation for service however as do Jasic which is another common brand in UK.
My Cobel one worked perfectly till a couple of weeks ago and I'll probably get around to trying to fix it one day. its very well put together using branded components and proper connections etc inside.
Needed one straight away however so bought this from Rally Design last week for £466 delivered from UK and its works great and is also well made
https://www.rallydesign.co.uk/produc...ducts_id=24137 It doesn't even say what the warranty is but you could buy 2 off these for the cost of an r-tech equivalent and generally these things get cheaper to make over time.
BTW - the "German" one mentioned above is likely to Stahl Werk brand. They are Chinese like the rest of them though it says something like "German designed and engineered" on the side. They say that in the case of a fault within 7 years they will collect from UK, fix it and return to you at their cost. sounds good at first but when you try to buy one it turns out they don't take credit cards but pretend that they do take credit cards! in fact, you are buying using your card via paypal which I think means you don't get CC protection so a little bit dodgy there although they also sell them on ebay for another £50. A friend's got one and it works well however.