In reply to STWright:
I don't think you need to pay any more than €20/ night. All the studios will do deals.
We've stayed in Appolonia (above the sponge shop), Afroditi (up the hill above the church), and both were fine. About €20, but we heard people were paying €15.
Try to get hold of a guidebook and think about where you might climb before you decide to rent a car/ scooter. If you're staying in Massouri, anything up to Kastelli can be easily walked. This includes Grande Grotte, odyssey etc. Anything beyond that, as far as Emporios, we just took the bus. If you ask nicely, they'll drop you off exactly where you'd park your bike anyway,. Only 3 buses a day, but they're perfectly timed for a half or full day.
We only hired bikes on one day to go round toVathy. They would also be handy for some of the other distant crags. You can always just hire for the days you need.