This is perhaps the cheapest accommodation I've seen online, P88 ONLY. Most affordable I must say for the people who would want to spend a great vacation in Puerto Princesa, the home of the famous Underground River.
Reserve now! http://gohotels.ph/
Follow them on Facebook at http://www.facebook.com/gohotels.ph
Call them at 3988788 / 3988119 to inquire about their Puerto Princesa branch.