Oxford has always cost more but the contract you're employed on isn't the same.
The Parc contract is around £50 / hour which, while running your own company, can lead to some very good months of pay.
CTC is 12 - 18 months (can't remember) but only at £1200 / month and I know of guys on that scheme who had to declare themselves bankrupt.
I'd rather have the higher up front cost but higher income so I am in a position to manage my own finances.