Hi, im looking to go around the islands of Koh Samui etc then onto krabi/ koh phi phi and was wondering would it be best to book before hand or will it be cheaper to book on arrival?

Ive heard that Koh Samui gets full quickly but also ive heard that you can haggle a better deal on arrival?

Also if anyone has any tips on hostels on the islands, looking around £10-20 ppn. Theres a few of us going so its not completely essential to have a buzzing atmoshere.

Cheers