erm referring to your question, there are restaurants around the islands..

there are a few resorts which fall around 400 - 600 per pax. even tunabay cause rm600 per pax for twin sharing full board last year when i went there.

just now when i checked their website, it is still rm600 per pax for twin sharing. i would highly recommend tuna bay as the staff there is very helpful and friendly! food is good too, 4 dishes for the dinner. 

this year im planning to make a trip there and probably try out scuba.. i m thinking of coral view island resort which is located right beside perhentian island resort. tripadvisor got good review on this coral view island resort, you can check the price too, 4xx-5xx per pax for twin sharing.

according to tripadvisor, perhentian island resort and coral view island resort are located at the best beach and got alot turtle spotted during snorkeling infront of the beach.

remarks: something wrong with coral view island resort website, cant load.
you can view this http://www.pulauperhentian.com.my/p_coralview_freeneasy.php to know more about the price

is at perhentian kecil, never been there. but from what i read from Tripadvisor, bubu is more like a luxury resort and more happening at night where ppl party around. by the way, is quite expensive

if you are looking for a simple holiday which does not put a hole to your wallet, i would strongly suggest Tuna Bay. Even i am planning to go again this year July with my family, im considering 2 resorts which are Tuna Bay and Coral View Island.
you can see at tripadvisor, these 2 are the rank #1 and #2 in perhentian besar.

Tuna bay if you re lucky to get beach front then is the best, and their beach is facing the sunset, every evening i just relax at the beach prepare my tripod for sunset photography.

as for coral view, i wanna try is because they have the best beach according to tripadvisor. during last year when i traveled there, our boat guide brought us to this place to see turtle. the place where we saw few turtles, is right infront this perhentian island resort and coral view island resort.

Tuna bay normal snorkelling full board only rm600..their dinner is nice, 4 dishes 1 soup for 2, somemore got 1 big fish