As long as you aren't leaving in Jamaica, you would not have to pay taxes on it. They do not check that you leave with everything you came with. Hint, hint. Throwing out the word "volunteer work" will usually always bring positive vibes from custom officials.
In all my trips, I have only been sent over to the "special" line once the guy who checked my passport was on a wee bit of a power trip and gave me the interrogation of a lifetime. I've never had to pay taxes on anything, even though one of my two suitcases are things that somehow get lost on my trip and never make it home with me. Hey, I like to travel prepared, never know when you might need a spare motorcycle part or car stereo while travelling in Jamaica.
It's not the taxes I mind, but the waiting in line, to have my personal things rummanged thru in plain site of returning residents who probably know my mother-in-law. The rumors would make it back to town before I did.
