For a start who quoted you that price the dealers? what was you total quote? yes, it is advisable to change the water pump at the same time as the belt.
It's advised to get the water pump changed with the cam belt but it's by no means essential, however, if the water pump happens to go before the next cam belt change you'll be paying for another cam belt change plus water pump to change it.
Up to you really, take the risk and save the money now but it might cost you double in the future, or get it changed now.
A new water pump shouldn't cost much more than £30. Maybe £40 inc. VAT. Most of the work has all ready been done to get to the cambelt and pulleys. I can't see where an extra £95 is justified.