You will be better off buying a camera than renting unless you are looking for Broadcast quality.
A standard rental price for a Sony PD-170 as an example would be £75.00/day £300.00/week.
Do not buy from e-bay as a lot of the bargains are suspect imports and probably NTSC format.
Your should pick up a new Digital Video such as a Sony TRV-22
for around £450.00