My first few times, I was a little leery about renting a car. But then, it dawned on me, I lived in a place (South Jersey) where the drivers are more brain dead and reckless than any tico driver will ever be, so I rented my first car after 4TH trip. There are a lot of options for transport in CR (public busses, micro-buses and private drivers), but the freedom and versatility to explore, visit and sight-see makes renting a car my #1 choice anywhere... especially if you are travelling with a group. Is that $240 for a full-sized SUV or a little "Terio"... also, does it include Supplemental Liability Insurance? The last time I was there, it was $20 per day.
Never had any real problems with rental cars in CR... except twice. Once was my fault... my foot slipped off the clutch at a farmacia in front of the US embassy near Pavas...and the bumper got slightly crunched by a concrete barricade. My amiga called INS, and they were out to scene within 5 minutes. The other time, I rolled down the hill from SL to Castillo with my novia dela noche and parked in front of the hotel where the nightwatch could clearly see my car. As my novia and I stepped out of the vehicle, one of the ninos dela calle asked me for C 500 to mind my car. I diplomatically told him to go "phuck" himself. Well, the next morning, Danny came up on duty, and got the run down from the nightwatch. The street urchin had busted the rear passenger window to punish me... but, I was told the cops got him. In both cases, my AMEX Premium auto rental insurance took care of all damages... not a cent out of my pocket.
Unless things have changed over the past 2 years in CR, it's safe to rent down there... no car thefts, being run off the road, etc.

Once you are out of San Jose, it's smooth sailing! Keep it locked up, take valuables out of the car, and look for "watched" parking and drive like "pura vida"
PS: Warning... the drinking driving laws are not as lenient as they used to be down there! Be careful! Take valuables out of the car, look for "watched parking" and keep it locked... then drive like "pura vida."