there are a few, but not many!
About 200-300 meters from the turn into Tamarindo near Santa Cruz (towards Liberia) off of the highway there is a place called Las Laureles. It is a bar/cabina place. From 5pm to 1 or 2am the place is packed with 10-20 girls, few hotties, but they do appear. Each girl has a cabina - prices vary from 10-20k, depending on the girl and how gringo you look.
About 10 min from Nicoya, going towards the bridge (Puente la Amistad de Taiwain) there is a place called Ricuras. It's a nightclub, opened like 6 or 7pm to 2 am, and usually has 5-15 girls. Also has on-site cabinas, and prices vary from 10-20k, again depending on the girl and how gringo you look.
About 10 min from Nicoya, going towards Samara, there is a bar called El Kuru. Open 11am - 12 midnight, 5-10 girls, talent usually on the low side. Prices are 10-15k.
In Samara there is a bar/cabinas place called Bar Mango, which has lesser quality talent, open 7pm to 2am, usually around 10-15k.
In Tamarindo there are several bars and clubs that all have working girls, mainly in the late evenings, but if you know what you are looking for you can find them at all hours at the beach, on the streets, etc.
Hope you find some fun!