I've used to agree on 450 baht toll included. Looking at this thread I might wanna start asking for them to use the meter. I actually did that once and got ripped off. The meter from Suvarnabhumi to Ibis Nana Hotel in Soi 4 showed 800 baht. I was shocked but figured the prices must've gone up hearing Thailand's economy was booming at the time. Quickly after I figured the meter obviously had been tampered with. A tad bit of an annoying holiday start but not a big deal.