Lesser known makes go for much less money, for example this Mitchell lathe is for sale for £1000 "buy it now" on Ebay.
Ebay
Recently I saw a nice well equipped old Lang lathe left unsold at £300 on Ebay.
Bargains are out there look, out for poorly described, dirty, poor photo, ETC.
And steer clear of dealers especially big ones like the above mentioned Electromotion.
P.S. good guidance can be had here.
http://www.lathes.co.uk/page21.html