It does feel like we change them too often but when DJ's are using our decks with such expensive vinyl, the £25 each does seem to be worth it.....
We also have spares for during the night if they need changing.
I do buy them off the internet though......I once forgot to buy new ones and popped into "sounds expensive", our local shop.......he wanted £35 each......I told him, you should be called "we definately are too bloody expensive" Got away with two for £50 for my cheek....