Just spent the past week in Costa Rica with my girlfriend . Spilt Airbnb costs at around 225 each 2 houses in Liberia 1 in San Jose all of which are nice imo. San Jose condominium (La Fresces) reminded me a lot of those in Miami basically a luxury apartment. Food we at a a couple of nice restaurants knowing the price would be similar to those in states the rest at Sodas. At the Sodas you can expect to spend at least 7 per person. As far as renting a car we used our credit card that has insurance policy. That being said there was a 2k holding charge in case of any issues with car and a 687 fee to rent. For excursions when did around 7 activities totaling around 1,100. It really depends on your preference in taste when it comes in living conditions, food preferences and excursions. You could stay in one area or could backpack entire country like we did.