If you're flanning on gong to uni, that helps a lot as you can get the student loans at around 0.5% interest

Remember to look at the other stuff you might require for the CBT, e.g. Collision Damage Waiver (usually around £15-£20) which means if you were to have the misfortune of crashing in to a car or damaging the bike, you wont have to pay the excess on the insurance (around £700 I believe). Also is the fee for the bike hire included in the price? And is the hire of any protective gear you require included?
Just as a reference for you to compare against, this is the company I'm hoping to re-do my CBT with:
http://www.camrider.com/prices/burystedmunds.htmlAlso worth noting if they have a "guaranteed pass" scheme. This simply means if you aren't riding to the required standard by the end of the day, you can go back another day and they'll give you more training for free until you get there.
Best of luck
