Exhausts are something than need replacing every few years. They might cost you £100 at somewhere like Kwikfit (fitted while you wait), more at a main dealer. CD players again are nothing to be worried about. The bearing, however, does worry me because they should not normally fail on a 5 year old car that has done 40k miles. Maybe at twice that age and/or twice that mileage, you should be listening out for problems. Similarly a clutch should last for more than 40k miles. In your shoes, I would be inclined to go back and say that it seems rather odd that both a bearing and the clutch should fail after only 40k miles and ask to swap for something of a similar age, mileage and specification to yours. I would also ignore the price as that's just a number that they paste to the windscreen. If yours is an 04 Ford Fusion with a 1.4 diesel engine and 42000 miles on the clock, they should swap it for something fairly similar.
Before thinking about your rights, you should first try to resolve things with the dealer.
Your rights are to buy something that is "fit for purpose" and something that is as described. Whether your car is was fit for purpose is debatable. I would say not but someone else may say that it is. Whether it is as described hinges, in my mind, on whether the mileage is correct. Most main garages will sell cars with a service history which should show the mileage moving on a few thousand miles between services to wherever it is now. Similarly the mileage at each MOT will have been recorded on the certificates. If the garage were to do a reasonable swap, I would do no more that raise the question with them about it being "odd" to have such problems at 40k miles. If not (and if you don't have enough documents to be convinced), you can check the records of mileage recorded at MOTs and, perhaps, when tax discs were issued on ths site (for a fee):
http://www.autocheck.co.uk/
It is also possible to get engineer's reports if you do suspect that the mileage is incorrect. If you can prove that the mileage is incorrect, you should report the matter to your local trading standards office.
If it is going to be you who pays for any work on this or any other vehicle, you should consider using somewhere other than a mail dealer - it will cost a third of the amount.