Not being a fan of all-inclusive resorts or beaches, I'd recommend Nicaragua over CR if your interests tend towards historical sites. Both Leon and Granada are Spanish colonial cities. Prices will be lower too. I did spend a week in San Jose for some surgery some years back; it was much cheaper than if I'd stayed home and had to pay 120% of my deductible.
I spent a couple of weeks last month in Ecuador, and it too has a lot to offer.