Tunabagel:
Do you have links or other information about ASOPTUR and the Alcaldia of Rurre ?
PJMccartney:
In your question I 'translate' the 'Madidi national park' into the rainforest = the jungle, south and west of Rurrenabaque, where the tours go by boat and foot. Contrary to the pampas where the tours start with a long drive on a bumpy road to the area of the Yacuma River, north east of Rurrenabaque and Reyes.
The jungle and the pampas are entirely different ecosystems, and the tours are entirely different experiences.
A tour in the jungle is absolutely recommendable, but the benefit depends a lot on your expectations. What each individual person regards as a good experience is different. All people are not alike.
See the thread Parque Manu or Parque Manini (= Madidi), 24-Oct-2008.
About prices for jungle tours I will recommend you to send mails to some of the tour operators. Updating websites and especially tour prices at the websites is not always easy for the local operators. And if you are able to write in Spanish, you may receive a quicker reply.
The prices will reflect the kind of tour, so investigate the websites and other information, and when you arrive at Rurrenabaque check with the tour operator before you decide. But remember that just now is the peak season, and if you have made up your mind beforehand then a reservation may be an advantage.
Some jungle tour operators (in alphabetical order):
Bala Tours
Chalalán Ecolodge
Mapajo Lodge (in the Pilon Lajas Reserve)
Mashaquipe Ethno-Eco Tourism
San Miguel del Bala Community Eco-Lodge
To learn more about jungle tours and tour operators search for: Rurrenabaque + tours jungle (with plus signs).
In the thread Animal friendly pampas tour?, 25-May-2009, I have written more about search technique and links about Rurrenabaque.
The Rough Guide about Ecotourism in Rurrenabaque.
WikiTravel at http://wikitravel.org/en/Rurrenabaque may also be of interest, but check the information elsewhere.
It would be nice, if you could come back here in the Bolivia forum and tell about your experiences.