Classicwings
You could be right with your figures. From what I can remember, the rate that has been negotiated with the hotel is £45 per night (which includes your breakfast in the morning). If you don't live too far away or you know somebody who lives nearby, check out at weekends to reduce the cost. You literally end up living out of a suitcase though, as you can't leave all of your stuff in the hotel room because you're unlikely to get the same room the following week! Might be worth it to save £90 per week though (not to mention the £30 for the meal vouchers for Friday and Saturday evenings) .
As the hotel doesn't have a dedicated restaurant a separate arrangement has been made with the Woodpecker (at least I think that's what it's called!) next door for evening meals. These are valued at £15 per night, paid for with vouchers obtained daily from the hotel reception - obviously, the hotel bills the college for these as well.
As far as lunch goes, the college has contracted a catering firm to supply these: you place your order with the college receptionist by 10am daily (menu's at reception to help with choosing), and your lunch is delivered to the college anytime between midday and 1pm. The budget for the lunch order is somewhere in the region of £4 or £5, I think. Doesn't sound like a whole lot, I know, but believe me it's enough to get a good lunch of, say, sandwich/baked potato, crisps, fruit salad and a couple of cans of soft drink. I think they might require COD from self-funding students though, so be prepared to have to pay when your order arrives.
There are a couple of water chillers in the students' common room, so I wouldn't waste the allowance buying bottled water (bring your own bottle and just keep refilling it), and there are snack and soft drinks vending machines also. There is a kitchenette with kettles and a fridge for students' use, but you'll need to bring your own tea/coffee, milk and sugar.