Eyup Gaz,as I said before mate I wouldnt buy anything as important as that on ebay.
Also you can pick up a Merlin now for not much over £200 which will give you loads more water than that.
You must remember that when they say its capable of 200 gpd thats exactly what they mean ITS CAPABLE.
Yes it is in ideal conditions.
Truth is with this system you would probably get about 300 ltrs in a 24 hr period
In short mate I would ignore it and buy a Merlin.
By the way we didnt take the job near Newmillerdam,crap parking,awkward for ladders etc.
We drove past and said sod it,trouble was she saw us and rang my mobile wanting to know why we drove past and didnt call
I just gave her the honest answer which was we didnt wish to take her on as a customer.