What is the fare on baht buses.
I can only quote based on my experience for the Green Songthaew and that is normally 10 baht during daylight hours and 15 when it gets dark.
I have a link see below that was last updated in 2014, but things have not changed much.....
Here is the information from the above link.
A songthaew is a pick up truck with two rows of seats in the back, and is one of he cheapest ways to get around the city, with prices starting at just 10 baht ($0.35). The songthaews operate along four fixed routes, with different colored songthaews operating each one. There are green, orange and white songthaews. The green ones cover Hua Hin Airport and Khao Takiab (10-20 baht), the orange ones cover Maegep, Market Village and Makro (10-20 baht), and the two white ones cover Hua Hin to Mongkol Temple (10-40 baht) and Hua Hin City (10 baht). Green songthaews operate 06:20-21:00, orange 06:00-22:00, and white 08:00-18:00 (Hua Hin to Mongkol Temple) and 07:00-22:00 (Hua Hin City). Just get on and off anywhere along the route.Edited: 08 June 2018, 05:09
10 baht and ruthenium 15 baht after 7pm