To go back to the flat screen TV - if it is not in a box and one says it is used - in our case that is true it is a year old - should there be a problem bringing it in?
I brought in a small (15") flat screen tv, which they looked at but let go as it was clearly also a computer monitor...
Same situation happened to a friend who brought in a 19" flat screen tv, he said it was used, but didnt mention it was a computer monitor...he spent over an hour negotiating...getting the aduanas down to 5000 or so pesos from over 9000...for a *used* tv that cost about $300 new...
both instances were over two years ago, customs does seem a little more "lax" these days at POP...
But...I believe that is the criteria...computer monitor is ok, a flat screen tv is not...used or otherwise...