Getting to and from Koh Phangan from Thailand or Malaysia is fairly straightforward. With Thailand being such a travel-friendly country, all of the transportation is set up nicely and is virtually headache free.
Buy yourself a bus/boat combo from Bangkok at any of the travel agencies. This seems to be the best way to do it. It’s very organized, efficient and a good price. We went from Bangkok to Surat Thani by a/c bus and then to Koh Phangan by speedboat for a cost of 500THB per person.
From the Thong Sala pier to Haad Rin, the cost is 100THB per person for a shared “taxi” – back of a pickup truck/songthaew
To Kuala Lumpur, Malaysia:
You will need to book a bus/boat combination ticket again. We took a ferry boat from Koh Phangan to Surat Thani, then a minibus to Penang, then we switched to a big bus that took us to Kuala Lumpur. The length of this journey was about 25 hours long and involved a lot more switching of transportation than we thought. Check out our Goat Show (video). The cost of this very long travel day was 1600THB/person…still cheaper than any flight we could find.