If you haven't been there, MA is for all practical purposes two towns, Quepos, the biz center with hotels (none recommended), restaurants, bus station, groceries, banks, bars, and all that, and the barrios, and then MA maybe 6 miles up and down the mountain all the way to the beach. There's hotels from one end to the other. Most of the very nice hotels $$$ $$$$ are up the hill on the road to the beach and maybe 5-10 minutes by car to the beach. A bus runs every 15 minutes or so but you have to get to the bus stops. Costa Verde may be your best shot at $100 in that area in Feb, has a web site, nice place, spread out, get as far off the road as you can. That's a problem in MA, there's busses and trucks chugging those hills from dawn to dusk and cabbies and moto's and jerks with loud speakers all night.
There are only a few decent ones near the beach in MA proper (defined as the area at the end of the road and close to the park entrance). Hotel Playa Espadilla comes to mind, a few blocks from the beach, nice, quiet. Has a website, (also has cabinas--but not for me). There's also a few dumpy ones in that area that look decent from the outside. There's only two right on the beach that are decent, Karahe as mentioned is one but get the one's on the beach side of the road--they're newer, but small; and Verde Mar, which I prefer over Karahe because you get a kitchen and a fridge, nice to have coffee and beer and snacks in the room. Bring reg coffee filters. From either you walk right out onto the beach. Both have websites. From either, you can walk to the bars/food in MA.
Wherever you stay, do not ask if they have a chica fee or a CRT discount--they will have no clue what CRT is, just check in with her and that's that. It ain't like SJ or Jaco.
There is some night life in MA on the main drag, and at some of the hotels on the road to MA, Hotel Byblos comes to mind, and some in Quepos, Sargent Garcia's comes to mind. Since you're bringing your own, you won't need to worry aout Pescadora, but it's a gringo hang by Best Western. Ask around for the current hot night club, there aren't that many but it changes.
Anyway, check out quepolandia.com for alot of info and a Quepos map, and
http://www.cupotico.com/maps/Manuel%20A ... 0maps.html for a very good hotel map from one end to the other with alot of links.
You will love that beach.