have been reading back through many posts about mongering adventures in Costa Rica.  It sounds like a lot of fun can be had if there is proper planning and one takes enough precaution.  I am going down alone and was hoping to get solid advice on where to stay on a tight budget, best/safest places for mongering, where to stay away from, what other things to do in my monger down time, and any other advice that I would need to consider.

You will have a ball.  Stay at Del Rey in San Jose and El Cocal in Jaco.  Both places very safe even if alone.

A lot of the cantina women in Costa Rica are seriously exploited and not willing..  They are forced by pimps to see upwards of 8 or more guys a day.  That's why a lot of them are so cheap.  I really don't think it's ethical to see women down there unless you get to know them and make sure they aren't being abused.  There are european and american men going down there to get girls under 18.  Makes me sick.

I'm not sure what you mean by "cantina women," and I'll stipulate that there are no doubt trafficked and under age women down here.
But also remember that Costa Rica strongly enforces its laws against underage sex. Prostitution is legal and regulated here.  If you meet a gal you can ask her to show her government-required ID card, proving her age.  And at most hotels she's got to show it before going up to anyone's room.  So it's easy to be sure you're not seeing someone under age or coerced.
The going rate for a hot, legal girl here is $100 an hour and many of them are asking $150-$200. Even at $100 an hour they are doing better than most of their countrymen, whose average monthly pay is not even $500.  A real looker can make that in a night at the Del Rey or the Cocal.
Facts are your friend.

I've been in Jaco for about six weeks and have seen several female "Johns" down here.  It's a lot of fun watching a woman cruise hookers.

and since prostitution itself is legal, any "pimped out" women are very easy to spot, and since no resources are wasted in harassing and arresting consenting adults, there are more available resources to use in fighting actual human trafficking.