It’s possible to camp in Parque Internacional La Amistad  for US$5, but as usual with Panamanian parks don’t expect developed campsites. There’s also a surprisingly pleasant dormitory at the ANAM station at the main entrance to the park for the same price. It offers bunk beds in shared rooms, a large fireplace, and a kitchen. Bring your own bedding.
For more information, ask at the station, or call the ANAM regional office in David  (tel. 775-3163; there’s a radio but no phone at the station itself). This place is a great deal.
There’s a similar setup at El Respingo ranger station at the trailhead for Sendero Los Quetzales . It’ll cost US$5 either to camp or to use a bunk in the quite decent ranger station, which is on a hill surrounded by nicely landscaped grounds. The view from here is stunning, and it’s a great place to pitch a tent. The bunks are in a small, dark wooden room that’s quite okay and has lockers.