I have a strange issue now. My originally booked included excursion became a select excursion some time ago. The price is crossed out, and, in my previous version of My Activities, it showed a unit cost for the tour of $0.00 and a total cost of $0.00. However, My Activities from March 22/24 continues to show a unit cost of $0.00, but the total cost now shows $159.00. However, when I look at the day on My Silversea, the price is still crossed off. This differs from another select excursion that I have chosen, where the price is in red and not crossed out. (They have also changed the name of the excursion, but not its content.)
I had my travel agent look into this, and the response she got was that I will have to pay. (I was on Bluetooth in the car so I wasn't prepared to talk to the person at the time, because I didn't have any way of making any notes.) She promised to give me the number of the person she was talking to, so I'll see if I can get this figured out.
As an aside, I double checked the Shore Excursion Terms and Conditions that I printed out when I first selected my excursions, and it says "Prices are subject to change without notice."