Many things in Mexico are quite affordable. Airport transportation gets tourist pricing. So the Ruta del Desierto bus to/from the San José del Cabo airport (or between San José del Cabo and Cabo San Lucas) can save a fair amount of money.
The bus travels from the airport to San José del Cabo, then along highway 1 to Cabo San Lucas.
Fare to or from the airport is MX$80, regardless if you only go to San José del Cabo or all the way to Cabo San Lucas. Still much more affordable than even a shared shuttle. At the airport, there is a uniformed man selling tickets at the bus stop. (If boarding elsewhere, just pay the driver.)
Fares between San José and Cabo San Lucas is MX$37. There appear to be other local fares, but you’re unlikely to score those fares with luggage or without speaking decent Spanish. (Something to work towards.)
The airport bus stop is located at Terminal 1. International flights use terminal 2, so you will need to make the short walk outdoors between terminals. (When arriving in Terminal 2, go upstairs to the departures level, then walk towards the side with a door. Go outside and follow that direction to Terminal 1. There’s a small sidewalk that goes the entire way, and you’ll pass car rental agencies and an OXXO.)
Their website lists their main stops, but doesn’t have a route map. The bus stops frequently, so you can definitely board or disembark between these main stops.
Hard to make much out of the bus stop map. A main stop in San José del Cabo is at the “La Comer” supermarket. In Cabo San Lucas, it’s near the “Puerto Paraiso” mall near the marina. The bus stops frequently between these mains tops, at the yellow-roofed bus stops along the way. When you see the purple and yellow bus, flag it down to ensure it stops for you.
When you want to disembark, the buses have the usual “stop requested” buttons. Or do like the locals and holler “bajar!” to the driver. Just be ready to get off quickly… they don’t stop for long.
Enjoy the adventure!