I checked the dealer on eBay & they do seem great value for money, although there ALWAYS seems to be a catch with 'too good to be true' prices. A typical example of this is a dealer on eBay who recently traded as Powershack, selling Chinese machines at unbelievable prices - they have since folded & buyers are now left high and dry with any kind of aftersales.
A web contact to the manufacturer can only be a good thing & you are only forking out 300+ pounds, so it's hardly gambling your house is it! My advice would be to go for a respected, established name (you even have to be carefull with that!) but you are then talking substantially more.
Your call.