If you want to get back to Don Muang from Rajadamri at night what's the best option?

How much does A1 bus cost nowadays?

In the past I'd get 504 but I didn't see the yesterday.

Yes I saw the 504 this morning on Silom road. There ain't too many of them around.

I think they may come every 30 mins depending on traffic but once I had to wait 55 mins for one. That was about 7 -8 am, so I am not sure if that was because they had to pull one off the schedule, or maybe they just leave their starting point at random?

I also would be interested to hear more about their timing from regular travellers on this route, as its the easiest way for me to get to DM.