Hi Mark,
I got the following reply when I asked about the optional excursions:
Hi Caroline,
I have list of our optional excursions for you:
Day 3 – optional full day to Agrigento and Piazza Armerina
Day 6 – optional full day to Segesta and Erice
Day 7 – optional full day “Unknown Sicily” excursion to Gibilmanna, Castelbuono and Gangi
Unfortunately I still don't know the cost involved as I decided not to do this tour this year.
Regards
Caroline