I've just checked. There's an orange TSR2 for £600 but up in Aberdeen, belt drive, rack, bags, guards, looks in good nick but not all TSR2s have the braze ons for derailleurs. Next price wise is an AM 14, but currently with 8 speed SA hub for £1250 in Devon. If you win the lottery there's an stainless steel AM Speed with Super Record - POA North London!
I got my TSR via a post on the Moulton Yahoo Group. Despite appearances it is still working and active (took a few days for my registration to be accepted). Any TSR on ebat seems to go for £1,000 plus, APBs come up in your price range though. Also try the CTC forum, a few Moultoneers on there.