Samsung pricing is usually pretty reasonable. Just have a look at the quality/feature set/pricing of the current handset range in both PAYG and contract phones.
I'd imagine the handset price for the F700 will easily match that of the current HTC range on Contract and SimFree.
I'm hopeful the F700 should be free on contracts around the £35 range.
does look a very good phone though, I was considering the Kaiser or N95 8Gb but I'm going to hold out for the F700 release now i think. It looks as though Samsung have implemented their own Front end to the Windows Gui more successfully than HTC did with the Touch.
Rumoured to be a mid October to early November release on Vodafone to tie in with O2's iPhone release. Unlikely you'll see it "Officially" from O2 due to competition with their own XDA range and the iPhone although it's likely you'll be able to get one on O2 from an independant store and the web phone retailers.