Hi Gerri,
Thanks for getting our books! Hope you find them helpful.
A ballpark figure for a vacation is tough since it is so person specific, but we’ll give it a shot. Assuming you spend around $200/night total for 4 people, $900 on a 4×4 mid-size SUV (cost using our rental car discount), and $300 on gas, you’re looking at around $4,000 or $1,000 per person. Of course, you’ll have to add on meals and whatever activities you want to do too. If you’re looking for detailed info on cost for food, tours, etc., we recently wrote an article that you might want to check out, Cost of Traveling in Costa Rica.
Hope that helps talk your friend into coming!