From Buenos Aires there are daily flights to the city of Puerto Madryn and from there you get cheap and direct transport service to Puerto Piramides. Also, you can access by land through National Route 3.
The Valdes Peninsula is a protected area, so we you must pay an access fee of around $ 10 for national adults and $ 35 (argentinian pesos) for foreigners.
There is only one bus a day between Puerto Madryn and Puerto Piramides, leaving Madryn at 9.30 and returning at 6. It costs 11.50 pesos each way, and the trip takes about 1.5 hours. It can be longer on the way out if the bus is full as there is a stop at the park entrance where the guard checks tickets to the peninsula (these can be bought on the spot or back in Madryn). Most people travel on pre arranged tours to Peninsula Valdes. These cost far more than the bus journey, however, they also include tours of the rest of the peninsula, something which cannot be done by public transport.
To reach the Peninsula Valdes you have bus services every day at 9 am returning to the city at 6 pm. In Pto Piramide you dont need transportation, just wlk the few blocks, I recommend walk along the beach, just for pleasure.
Of course you can rent a car too, and with a map in your hands wander the whole Peninsula (take your time, is huge) Drive safely, the non paved roads (pebbles indeed) inside are dangerous at high speed.
Anyway, you can rent a car in Avis, for example.
watch address : Julio A. Roca 27, Puerto Madryn
We went from Montevideo (Uruguay) to Puerto Madryn (Argentina) by bus; it took 27 hours. After three days in Puerto Madryn, we went to Península Valdés in "our" bus, but there are regular buses from Puerto Madryn to Puerto Pirámides (104 Km); of course, you can drive your car.
Fuimos desde Montevideo (Uruguay) a Puerto Madryn (Argentina) en bus; nos llevó 27 horas. Luego de tres días en Puerto Madryn, nos fuimos hacia Península Valdés en "nuestro" ómnibus, pero hay servicios de línea desde Puerto Madryn a Puerto Pirámides (104 Km); por supuesto, pueden ir en su propio auto.