Here is a rather large map of Ko Samet Thailand.  It will take you 331 seconds to load on a 28.8 modem, but it lists all the bungalows on the island.   This page should fit squarely in your 1024x768 browser. This is actually a picture of a map located at the Na Dan pier, if you want to see the original. 

The island is 6 km long.

Some prices from my last trip (Jan 20,2001)

Roundtrip ferry to Nadan - 100 baht
Entry Fee to park - 200 baht, 20 baht for Thai.
Bungalow at Ao Phai - 500 baht.  (Double bed, fan, squatty toilet, electricity from 6pm - 9am)
Air Con room - 800 baht.
Watermelon Shake - 30 baht.
Beer at Naga bar - 60 baht, (bad) Singapore Sling - 100 baht.
Transport from Ao Phai to Na Dan in full truck - 20 baht.

Links:
Phone number of places in Rayong and Pattaya.
BUNGALOW IN RAYONG
kohsamet - Halfway done site.