Transfers

By Air - You can only drive to the places along Costalegre - or arrange for ground transportation from the Airport to your hotel or luxury resort. You can fly to Puerto Vallarta and Manzanillo (which both offer access to Costalegre) from the United States and and other points in Mexico including Guadalajara, La Paz, Leon and Mexico City.
By Bus - You can travel to Puerto Vallarta or Manzanillo on a luxury bus from Mexico City - but note that the trip will take around 14 hours (12 hours to Manzanillo from Mexico City). Flying is the most sensible way to get to Puerto Vallarta or Manzanillo, unless you are on a budget, and don't mind the relatively long bus journey (which is also quite mountainous, especially to Puerto Vallarta).
By Car - The road journey to Puerto Vallarta from inland Mexico (e.g. Guadalajara, Mexico City, Chihuahua, et al) is mountainous and winding. Expect it to take longer that you may anticipate; especially if you have not driven the route before. The easiest route in and out of Puerto Vallarta is by using Highway 200 -- the coast road -- although if you plan to go inland to Guadalajara or Mexico City, then this road will take you out of the way you really want to go. Traveling out of Puerto Vallarta by road north to Punta de Mita, or south to Costalegre and Manzanillo is straightforward: the roads are good and the terrain is easy to negotiate in a car.