Jason,
I'm a fellow Thai monger. But since I just got back from CR in Feb, I'm not going to be going to Thailand any time soon. I still love the place, but I just can't bring myself to go back over Costa Rica. I've already booked trips in May, Sept, and Dec if that tells you anything.
Everything I like about Thailand is either matched, beaten, or just shy of Thailand. And when you factor in travel time and cost, it's hard to beat Costa Rica.
The only downside is that the action is mostly in San Jose and the nature is away from the city. You have to do both if you want to get the full picture, but this is no downside if you're comparing it to BKK Manila or Angeles. It's the same there.
Hotel, $70 gets you a room in the most popular place in town Sportsmen's Lodge (just like Giotto's place in Bangkok, Livingstone's Lodge, but more fun to hang out in).
Beer, so cheap I don't remember the price, never noticed. Same as Thailand really.
Girls, pulling from the Del Rey is equivalent to pulling a bar-girl from Nana . Total damage in Nana is probably $65-75, Del Rey is $60-$100. But those girls at $100 are top notch, better than Thai bar girls, and definitely better sex. The Chicas are hotter experiences on the whole (and you're hearing that from a guy with a bad case of Yellow Fever). I've had almost nothing but Asians for the last 10 years, and I'm hooked on Latinas after one trip. I still love Asians, but don't knock the Latinas.
The unspoken advantage is the travel time. 4-6 hours to CR, or 24 to BKK? Hmm, let me think. 12-14 hours of time difference, or 0-1 hour difference? Airline miles costing the same as a flight to Oklahoma City, or your right arm and half your right leg? Not even bothering to break out your laptop on the flight since you don't even really have time, or having to break it out to watch movies on the flights to keep your head from exploding at the mind-numbing hour after hour flights,? Being able to go and come back so quick that it doesn't even really count as a trip versus everyone thinking you've dropped off the face of the Earth for a month and are shirking all of your responsibilities at home? Being able to look someone in the eye and tell them about the amazing topography, horticulture, and wildlife with them thinking you might actually be a redeemable human being (perchance maybe even an environmentally responsible traveler),
or not even bothering to hide the fact that everyone thinks you're a dirty disgusting monger who defiles poor innocent farm girls who's parents probably sold them to some evil bar owner.
Am I persuading you?

Costa Rica Rocks!