For boat ticket to Phangan: only at travel agencies or can I also buy it at the pier just befor departure?

your best to buy from travel agent, as they are the same price anyway ...

...or at your reception and some ferry operators will pick you up from the hotel...

...or you take the Had Rin Queen from Big Buddha pier directly to Had Rin at 1030, 1300, 1600 or 1830. Had Rin??... ah yes, that's the beach with most tourists=backpackers on KPG.

...so much for the OPs travel expertise

You can also buy tickets to Phangan, Tao or Nang Yuan at Lompraya pier (Maenam beach) in their office. Pick-up from your place is included into ticket price. Lompraya catamarans are really comfortable.

You can also buy tickets to Phangan, Tao or Nang Yuan at Lompraya pier (Maenam beach) in their office. Pick-up from your place is included into ticket price. Lompraya catamarans are really comfortable.

but try and book in advance, as sometimes it is full

You can also buy tickets to Phangan, Tao or Nang Yuan at Lompraya pier (Maenam beach) in their office. Pick-up from your place is included into ticket price. Lompraya catamarans are really comfortable.

500 Baht from Lamai to Menam by taxi and afterwards that lost fellow buys a ticket somewhere from a relative of the taxi driver for the last buffalo fight before he pays 500 Baht back to Lamai.

you can buy that tix everywhere, as already mentioned.

Thanks for the tips. Bought a ticket at the reception of my acco. Only 250 from lamai South to KP.