However, one thing that they've neglected to mention ... if you're buying the car in Costa Rica, and you want to bring it into the USA, then there may be import duties. You might be paying some percentage of the purchase price (listed on the bill of sale.)
Please fly. Check out deals with spirit airlines and travelocity. There are drug gangs in Mexico and other countries that are just not making it safe to drive now. Do a google search - there was just a marine that went through hell over seas and wanted to go to Costa Rica for some r & r. Well he got captured by a gang and was held for weeks and is darn lucky he even got alive - and that was probably only because the media got a hold of the story. Your being American will mean nothing to these people.
Fly in to CR and you will be pretty safe and able to rent a car for where you want to go. But don't drive through mexico now!
The two answers given are very good. Just to add, something. There was an article recently in the Costa Rican papers on truckers who went from Houston to Costa Rica. Even tough old truckers only travel in convoys (5 or more trucks) and never drive at night in Mexico, Guatemala, Honduras and El Salvador (they are parked well before sundown) and often hire armed cards to protect them while they are parked/sleeping. If you are looking to save money--this is not a good idea. If you are looking for heavy adventure it may be.
That is over 3,600 miles and would take at least 8 days to drive. You would have to drive through Mexico, Guatemala, Honduras, and Nicaragua. You will need to get car permits and car insurance for each country you will be driving through. Road conditions can be from good to horrible. You will certainly need to speak Spanish. If you get 24 miles to the gallon then gas will cost you about $530.00. You will have to pay for motels and food, too. You CANNOT safely drive after sunset in Mexico and Central America for many reasons...including animals on the road and holes in the road big enough to swallow a VW beetle. You will get a tourist card at the border of Mexico and Nicaragua and do not need visas for the other countries. You will need to get a car permit and car insurance at the border of each country. The weather will be hot and hotter from now on and rainy season with torrential rains begins in a few weeks. See articles below.
I am wondering how much gas it will cost to drive to costa rica from north carolina? i need to know it is about $3.50 per gallon here also how is the weather???? in CR? and the places you drive throgh to get there.