I was browsing the web and found only one up-to-date information about the Three pagodas pass in Sangkhlaburi from May 2004.

Border crossing (day pass) into Myranmar cost 10 USD and the passport will not be stamped.

Does anybody have recent information if it is possible to re-new a multi entry visa at this border nowadays?

I was there about two months ago and it's still wasn't an official international border crossing. Locals can obviously pass but tourists have to submit their passport to the Thai immigration office in town and will be given a receipt. You show the receipt at the border about 20 kms away at the 3PP and pay a fee.

I enquired about this to the Austrian owner of the Burmese Inn in town and he's always enquiring and being told 'next month, next month, next month.....'.

Perhaps one day it will be open. I hope so

Gazza

Locals can obviously pass but tourists have to submit their passport to the Thai immigration office in town and will be given a receipt. You show the receipt at the border about 20 kms away at the 3PP and pay a fee.

That is also the way the system worked at the Thai-Myanmar border in Mae Sai until about 1998 or so when it was changed to a "real" entry/exit point. I'm not sure what the impetus is for upgrading a border crossing as such but no doubt that there is some financial aspect involved.