Timetraveler,

I don't see there is anything wrong with sending a nice e-mail to the hotel telling them you have noticed their lower rates and that you would like to benefit from the promotion.
This has happened to me a couple of times and the hotel has honored the lower rates.

I would strongly recommend the Hotel Barocco, a wonderful small boutique hotel in a great location. It was myself, my husband and our three kids and we walked everywhere and it was perfect!