@Teddy ***********
I live in Pattay and I take a van to Cambodia. Cost is about 3500 baht and takes about 8 hours.
I recently bought a one way ticket from BKK to KLA for $50, I don't know what a round trip ticket would cost. I believe the 8 hour round trip road trip preferable. After factoring waiting for the return trip, waiting 2 hours before flight, travel to/from the airport, the road trips just makes more sense. Plus I am probably saving the planet.