Other cheaper mongering destinations:
Nicaragua
The Dominican Republic...the Boca Chica, Sosua and Puerto Plata areas in particular
Cuba... but that may pose some problems for a U.S. citizen
Honduras
From my reading, neither Panama nor Mexico are cheaper than C.R., and Colombia is a very YMMV thing. If you stay at someplace like the Medellin Mansion, it can be more expensive than C.R.
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Jaco Beach as Pacifica55 notes is a hot, humid beach town with limited mongering opportunities, although action there has been reported to be good as of late. It is the closest Pacific beach to the capital, San Jose. Like Pacifica55, I recommend SJ for your first trip. Poon prices range from $12.00 in the lowest-end massage parlors, up to "the sky's the limit" at the clip joint strip clubs. Nice tail can be rented for $60.00 - $80.00 at places like the Hotel del Rey, Key Largo club and other places where independent professional women congregate.
Beware the Presidente: It's a very nice hotel, really. WIFI, casino and restaurant (the News Cafe) on premises, A/C, some suites with jacuzzi tubs, very nice. They are however only tolerant of hookers; you're limited to one female guest at a time (no threesomes), and many of the girls who work the del Rey have been banned from there for infractions as serious as theft from guests to things as minor as dress code violations or failure to return their visitor pass at the front desk. The hotel enforces a dress code for the girls...but a birka or nun's habit should be fine. I exagerrate a bit here, but they are very strict. No deep cleavage, no bare arms, no bare bellies, no skirts above just above the knee, etc.
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Backdoor: Your mileage will vary. Read Pacifica's advice, above.
HTH
Paul
P.S. Welcome to CRT!
Zeus