Prices vary dramatically and shopping around is recommended. July and August prices are substantially higher than the rest of the year. Most car hire companies require that the driver is over 21 years old and has a clean driver's license. It is not permitted to take hired vehicles into Sinai or over the border to Jordan. Taxis are widely available in Palestinian cities.
Fares are negotiable.
An inexpensive alternative are Service Taxis. These are usually stretch Mercedes seating up to seven passengers, or Ford Transits , which operate on a fixed price just like a bus. If uncertain about the fare , just ask fellow passengers. Most of them travel between towns and cities from recognized taxi ranks, departing when they are full. This might involve waiting for six other people but the system is very popular and long delays are rare.