For example, if I take a taxi from Cabo San Lucas to the airport, I will be charged $50 USD plus tip for one person/one way. If there is more than one person, the price increases. If I purchase "Roundtrip Transfers" I will be charged $34 USD roundtrip plus tip for one person.
A company that I recommend is Cabo San Lucas Tours. Their website is www.cabosanlucastours.net Their website is very easy and explainable. You can make the payment with a credit card and they will email you the voucher. You must print the voucher and take it with you. When leaving the airport you will see a representative outside of the terminal in a bright orange shirt. If you choose to have shared transportation, you will be waiting for others. Shared transportation is the cheapest roundtrip and you will be stopping at several resorts to drop off others. The representative will give you a voucher with the time of your pick-up for departure. I suggest calling Cabo San Lucas tours at 01-800-822-4577 a few days before your departure to confirm. You can also contact them to see if the departure time has changed. Sometimes if there are not many reservations for pick-up, the times may change. I have used this company several times and they are reliable. They are pretty quick at leaving the airport and they have been on-time for departure to the airport.
Are you traveling with a large group? Cabo San Lucas Tours also offers private airport transfers. If you are staying in a condo or home and would like to stop and do your shopping on the way, they can accommodate that as well for an additional charge.