Tourism on Ko Phi Phi, like the rest of Krabi province, has exploded only very recently. In the early 1990s only the most adventurous travelers visited the island, staying in only the most basic accommodation costing the likes of 50-100 baht a night. Nowadays, however, the place has turned into one of the major destinations for visitors to Thailand. The development however, is still nothing on a par with the likes of Phuket or Ko Samui.
However, presently, budget backpackers can still get a cheap room away from the beach, up the hill a bit.
Ko Phi Phi has plenty of night life, but if that isn't your cup of tea, then there are lots of really quiet places to chill out and take it easy.