Read my exact words again. I thought before I posted and chose my words carefully - so I would NOT be telling them to lie. I only gave the OP a valid reason they would bring a small, used TV that would not subject them to duty.
If they decide at the end of their vacation, they don't want to bring it back - for instance, not enough room in the suitcase with all the souveniers - that does not mean they lied on any forms when entering the country. As long as they haven't actually made up their minds to leave it, when filling out the forms, they are not lying.
As far as prices, I'm in this exact position for my upcoming trip - trying to decide whether to bring down a TV for my home in Negril or buy in Jamaica. Believe me, I've been trying to find on-line prices for TVs in Jamaica - there is very little on-line info. Courts is one of the few - but still very limited. I am seeing prices at least double what I can buy for in U.S. So even paying the extra bag fee to make it one of my checked bags - it looks like I am saving $100's. Granted this is for a new flat screen TV, not a used 19" old-style tube TV.
If someone can definitely tell me where there is an electronics store between MoBay and Negril, or Negril and Sav, where I can get a 32" or so TV for about $300US - that would save me a big hassle. I'll buy you lunch.