To be honest - I think you may need a bit more...that's only just over £100....unless you are staying half board and intend to have all your meals at your accommodation.
We only just made it on £250 per person...it IS cheaper over there, but you do tend to overdo it on the drink (well, you're on hols aren't you?!)...and it all adds up.
I'm sure it is possible on a very tight budget - but just remember that you have to buy ALL your drinks (apart from the breakfast coffee if you are HB)