1849-1850 Costa Rica Real

For an F-12 specimen you should be paying around $15.

Not for at least a few years... For the 1849, even though it's rather common, average circs (which are somewhere in the VG to F+ range) bring around $35-40 now. The 1850 is tougher - expect to pay somewhat more. Costa Rica has become very popular in general.

Lithianial, you specifically mention the 1849-50 type, so I would suppose you like the "Coffee Madonna" design (note that the 1847 1R also has essentially the same design). As alluded to, that design was only used on a 1 Real - nothing bigger (1R was, in theory, 1/8 of a "peso" aka 8 Reales... though this 1R had been somewhat debased from that original standard). Note that the Central American Republic sunburst 8R mentioned is also a popular style (probably even more so)...

Insight? Not sure exactly why... but a similar effect has occurred with Chile, Ecuador, Venezuela, Colombia... I think it goes along with seemingly more collectors in general venturing into specialty areas of the post-Spanish Colonial coinage. Perhaps an even more important factor could be increased disposable income as those nations' economies develop (though Venezuela? maybe the friends of the regime...). That same effect, of course, has driven Chinese and Russian pieces over the last decade... and look how Chinese interest has pushed Spanish Colonial/Mex Cap & Rays...

Speaking specifically of Costa Rica... I would be tempted to also consider all those No. Amer. expats who maybe now show an interest in their adopted country - they often fall squarely into the coin collecting/disposable income demographic.