Currently trying to plan a month long trip split between Costa Rica and Sosua, DR. I'm in the process of fine tuning the logistics between my destinations, particularly from SJO to San Domingo, DR. I have found, after some googling, that TACA airline offers direct flights from the two cities for a decent price (a little less expensive than a RT flight from Chicago to SJO). Now TACA is new to me and in fact I never knew they existed until today. So I hit the search button for some insight/opinions about this airline from the members of this site and....OK, not bad...sound like a legit company...I'm sold. So now I know how to get to Sosua but I do have some questions regarding traveling between the two airposts (I don't really like surprises unless they involve the words "good" and "Chicas"

).
So, first off, do I need to purchase the $26 tax stamp when I fly out of SJO to San Domingo, DR like when I depart for the US?? Having never stepped foot inside of SJO, what is the best time of day to travel (meaning when the airport is the least busy)?
Regards.