They extra money Ktec have added on gives you some peace of mind, the knowledge that if they do go wrong they are at the end of the phone to help.
My set that I bought on ebay for less also have a 2 year warranty, but obviously I'd have to probably remove from the car and send back to Germany after firing off a few emails.
You pays your manoey, you takes your choice, except perhaps you don't, because i'm not sure they're available on ebay anymore.
I totally agree with the 'piece of mind' and probably would have bought from K-Tech for the little extra if this was available sooner, but mine were shipped on Wednesday.