I'm not promoting any specific service, but if you are in a time-bind situation to go see Bangkok, etc., for about $60 you can just book a fast-track entry coupled with a car to take you directly where you want to go without worrying about tolls, meters, etc. Even if you are polite and give the bag carrier dude 100 baht tip and 100 for the driver, you are still less than $70 for an easy, sure, quick access to the city. I understand some students-budget travelers will recoil at the idea, but if you can afford it, it's really very simple. Especially if you have less than 24 hours, etc.