You can easily arrange a bus from Krabi to Surat Thani (and possibly direct to Don Sak and/or Samui). I can't recall where the bus station is in Krabi so maybe just ask around some the local agents in Krabi or even at your guesthouse to get an idea of pricing. If you made your way to the bus terminal you may be able to arrange it a bit cheaper. The bus ride between Krabi and Surat Thani is approx 5-6 hours I think.
Hopefully someone will pop up on here with more specific details.
Plenty of agencies on Koh Lanta will sell you a package ticket that's comparable to the cost you'd pay if you pieced it out and did it yourself. Minivan to Krabi town, bus to Don Sak, and then ferry to Koh Samui. Quite easy to do yourself, but maybe you'd prefer an agency help you out.
#3 whardy has been a member since 14/11/2011. Posts: 66
Thanks! I will get a transport with mini-van and ferry from My Ao Nammao hotel to Koh Samui for 500 bath, which seems fair. Local transports are relatively more expansive in Thailand's touristic areas, than longer trips.
#4 Andris has been a member since 24/1/2012. Posts: 2