U can stay in hotels not much near by to beach .so u can save money took ....
and the cafes and pub are allround .. for night life enjoyment I suggest u can go to Varkala ... much better than kovalam
I had visited Koovalm in September and trust me you can get good hotel near beach or near Light house(Cafes and pubs are near to Light house). I have stayed near Light house and it was a great experience.