You can rent satphones online from several places-here are a couple-
https://www.satellitephonestore.com/rent/
http://www.allroadsat.com/?gclid=CImnrLWBu7MCFYN_QgodFxAAnw
http://www.mobal.com/satellite-phone-rental/

Not necessarily cheap, but cheaper than buying and far better chance of coverage than with a cell phone.
On the other hand, a PLB is a one time purchase.
BTW, I made the mistake of making a pay phone call from the ski lodge at Badger Pass in Yosemite. A five minute call cost me $20. There is cel coverage in the Valley, but not once you leave the Valley, at least there was none a couple of years ago. It may be better now.