If you cash a lot of dollars into colones, please exercise prudence. Don't flash the cash, take a taxi back to your hotel/room safe.
Best places in order of exchange rates/convenience:
Banks: Best exchange, "banker's hours."
Casinos: Second - best exchange rate, 24 hour access? Well, access when the casino is open.
Worst:
* Money exchange right in the baggage/customs area. If you need cash going into town, cross the street to the arrivals area and use the exchange kiosk (actually a mini-branch of a bank).
NEVER trust street money changers. Mighty fine counterfeit comes north from Colombia on a fairly routine basis.
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You should still contact the condo mgmt. to determine guest policy. Condos should be reasonable about it...but you oughta ask.
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Dresscode? Not at the beach! Shorts, sandals, polo/golf/tee shirts. No worries.
Lots of guys prefer jeans or long pants while in the capital. Most ticos do not wear shorts in town...and those who do are inevitably teenagers or younger.