Would there be a minibus shuttle from the cruise terminal to Runaway beach? We would prefer this to using a cab.
No shuttles, I'm afraid. A taxi for up to four people travelling together is US$12 each way.
Another option is to take bus #50 from the West Bus Terminal. The bus does not drop you off right at the beach, and there would be a bit of a walk (1.3 km) to get there, so it is not for everyone, but it can be done.