We had read that the best chance to view the crater and lagoon were in the morning. We considered taking the bus, but thought it would get there too late. Instead, we hired a taxi (if you can find other people in your hotel that are interested in the same things, you can split the cost). We left San Jose at 7am and it took about an hour and a half to get there. It cost us $10 per person to get in which appears to be the non-resident price. It might be cheaper for locals.
We walked up to the crater and had excellent views. We then hoofed it up the trail to the lagoon. Asthmatics, bring your inhalers. Couch potatoes, prepare to take a few rests on the way up. The altitude combined with the ascent will kick your butt if you aren't in shape.
We had 15 to 20 minutes of clear views of the lagoon before it was completely covered by clouds. Instead of going back the way we came, we continued on the loop. It was probably about the same distance, but it was uphill and then very steeply downhill. The jungle was beautiful, but walking was slightly treacherous due to slippery leaves and a lack of handrails which were removed for some reason.
We compared the prices of some of the things in the visitor's center gift shop to other stores and didn't find them to be completely outrageous. The bathrooms were clean.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.