I guess you are right, the last night is priced at $179, cheaper than what I booked.

As a matter of fact, I booked the 3rd night again separately to take advantage of the lower rate, that is why I tried to drop the last night of my initial booking. That's happened before with the same hotel and I encountered no problem then.

I did try to modify my initial booking online without success, since the system just repriced the reservation to the higher rate.

Well, I will keep an eye on the rate but I doubt the rate will ever come down for the first 2 nights, since it is a convention week. If nothing favorable comes up, I just cancel the cheaper 3rd night, sigh...

Thanks for all the feedbacks,