$80 for a trip to Sav is good price, as Hussyband said. We combined a trip to Sav with a trip to Abekuta and paid our driver $120 for the 2 of us. But as Bnewb said the price will depend on how long your trip is.

The first thing I do when I get to the hotel is put our passports (and other valuables) in the room safe. I used to carry around my US Drivers License, just in case anybody asked for ID. For example, If I lost a room a key and needed to prove that I was actually registered at the hotel. However, at the places we stay the managers, owners, etc. know us by name so that has never been an issue.