ray
cctv is quite specialised equipment, its really not just a case of sticking a couple of cables in annd plugging every thing together.
the quote you had does sound expensive tbh, i persoanlly dont like wirless as wetaher conditions and site conditions can effect it severly. one of the problems that wirless transmission cause is becuase wirless signals in britain are mainly 2.4 ghz, if anyone has a router with wireless, or they also have other equipment in range that is the same frequency then this will interfere with your wirless equpiment, also if it rains hard, had gales or high winds then again this can make the signal become weak etc.
if you can get a duct put in the ground then wiring will be alot easier and if more cables have to be installed.
regards
fs