Hospitals usually provide them if you need one while you are a patient. These pumps are wonderful and virtually painless. While in the hospital, pumping every 2-3 hours is a good way to get the milk flow started. Once you are released from the hospital, if your child is still a patient, you need a good pump for your home. You have several options, here.
Prices vary depending on pump and area.
If you want your own pump, there are several good ones on the market. Manual pumps are usually harder for most women to use. They require you to pull or press a lever to pump the milk. The AdventIsis is a wonderful manual pump. It also has the speed of an electric.