The K800i on Vodafone is £72 on PAYG. It will be locked to their network. You could get it unlocked for £10 at the local market stall or private phone shop, total outlay £82 which is pretty good value for what it is.

It would probably cost as much to repair the handset.

Water and handsets just do not mix - best keep the two as far apart from eachother as possible.

PS - On Orange it is £59 but you have to buy a £10 top-up voucher with it, so maybe not such a bargain unless you are already on Orange.