My experience and advice on a Manuel Antonio side trip:
Airline booking:
You can get the least expensive tickets through Nature Air. There are three categories Elite (the most expensive, but you can make the most changes to your itinerary), Promo (moderately priced and you can make some changes to itinerary, and Locos (the cheapest, but you can't make any changes to your itinerary once you have booked). You have to book fairly early to get the "Locos"- least expensive tickets.
Sansa Airlines has a few more flights going to and from Quepos, but they don't give you different choices. I have flown to Quepos twice with Sansa and both times the return flight was 30-40 minutes late.
If you want to do a day trip, you can fly out in the morning and take the last flight home (around 5:00 p.m.). You could also take a bus, taxi, car rental, or shuttle to Manuel Antonio. The downside is a long drive (anywhere from 3-5 1/2 hours depending on traffic, weather, hotel stops if going via shuttle,and current road conditions).
Quepos Airport: Very small airport with two airline counters (Nature Air and Sansa). If you have hotel accomodations, a shuttle will meet you there. If you are going to day trip route, you will have to take a taxi or talk one of the shuttle drivers into taking you to the park. Manuel Antonio Park is about a 20 minute drive from Quepos airport. It can cost anywhere from $6 for a shuttle ride to $12 for a taxi ride to the Manuel Antonio National Park.
Manuel Antonio National Park:
There is a beautiful stretch of beach that lies just outside the park. This area is free and open to the public. Their are vendors there, surfing lessons, boogie board rentals, chair rentals, etc. There are guide that are outside the park and they will offer you a guided tour that costs about $20 per person (you need at least 3 people to go on a tour, but you can wait for other people if necessary). The guides have telescopes and will take pictures of the wildlife for you through their telescope.
To access the park, you need to walk to the end of the beach and up a small hill. Sometimes due to the tide, you have to take a small canoe across a pond to access the entrance (the charges you about a dollar for his service). It is $6 to enter the park. The park is open from 7 a.m. to 4 p.m.and is closed Monday. There are several different hikes to take in the park and there are bathrooms along the way. There are also several beaches located inside the park. The first beach comes up very soon to your right. If you proceed forward along the winding trail, you will eventually come to a fork. Stay to the left and you will find the 2nd beach (my personal favorite beach). It is set inside a cove and is very peaceful and there are also a few tide pools. Several monkeys came out of the trees and were frolicking around when I was there. If you choose the right fork, the trail gets a little steeper and you can access the other beaches as well as a lookout point. There is also a wrap-around trail that will take you back to a side entrance of the park (on my first trip this is where I saw the sloths in the trees with the help of a guide).
If its your first trip to the park, I would recommend a guided tour (it lasts about 2 hours). If you have already been on the guided tour, you can just explore the area by yourself and hangout at the 2nd beach for awhile.
Restaurants:
There are several restaurants near the park entrance. I had lunch at the Marlin restaurant and really enjoyed it. The service was good and they had several local seafood and American type cuisine. They also have a full bar. You could also take a cab to any number of hotels in the area that have nicer restaurants.
Upside to the Manuel Antonio side trip:
You get to see a beautiful area and taste a different part of Costa Rica. You can take several pictures and impress your friends and loved ones back home. It also makes it seem like more of a "legitimate" vacation rather than solely a mongering trip. The day trip also allows you to get back to the gulch for primetime.
Downside:
Cost- it will cost one person anywhere from $120-$220 for this day trip. You have to taxi to the airport from downtown which costs around $15 each way. Then you have your taxi or shuttle to the park and back. Of course the cost of the plane ticket as well.
I would not recommend a day trip unless you fly. If you shuttle, bus, drive a rental, or taxi- at least stay for one night. There are several inexpensive hotel options and there is a little night action in Quepos and Manuel Antonio.
Resources:
http://www.natureair.com/
http://www.flysansa.com/
http://www.manuelantoniopark.com/mapk/english/park.html
http://www.frommers.com/destinations/ma ... nddin.html
http://www.frommers.com/destinations/ma ... ndacc.html