These were the costs for 2011/2012 - bare in mind it might change the next academic year.
You'll need to join Warwick Sport which is a £49 fee for the academic year.
Then you will have to pay £40 on top of that to use the Strength and Conditioning Room (the weights room which includes Olympic barbells, lifting platforms, squat racks, benches and others).
So a total of £89.
But if you want to be able to use the fitness suite (Running Bear Fitness Suite) too which includes a ridiculous host of machines and elliptical trainers, rowing machines, treadmills, then you'll have to pay £99 which will include access to the Strength and Conditioning Room.
So there are two options: £49 - Warwick Sport joining fee plus a) £40 to use only the S&C room or b) £99 to use the S&C room and the Fitness Bear Suite.