Go on Ebay, look for Harrison Hire & Sales. i bought one off them for £125 + Vat & delivery.
The thing to watch out for on that machine, inside the waste tank there is a pipe on the right with a bit of sponge in the top.
Dont use it without the sponge in place as it filters all the hairs and fibres from sucking into the motors that you are looking at and clogging them up causing them to burn out.
Keep a spare bit of sponge with you and check it regular to make sure it hasnt popped out whilst using it.
I replaced both motors because of this.