I still think for a few $ it isn't worth it, but also there must be an element of gauging what the taxi driver looks like, etc. if it is worth it to make a few comments but pay up, or to actually make the point and pay less.

On another note, I took the BMW again, 2,200 baht + 100b tip, it is a very pleasant ride home from the airport, even during rush hour. Seats recline way back but it would be nice if it had a little minibar I think the driver was burning spa therapy incense or something, totally relaxing, no stress.