I actually didn't know they were worth anything. I just found them today when I was cleaning out my parents storage closet. They were given to me while I was at the 1999 Tropical Mega Battle in Hawaii. One set was given to each of the trainers, so I imagine they are very rare. An identical copy of the exeggutor I was given later came out in a Japanese magazine, so it was nothing special. I placed second in that tournament and will never forget my time there.
Hahaha what a find!! How many compeitors were there? I was under the assumption they were won in timed battles. Anyway if there is anything you would not mind parting with feel free to pm me! I bet that was an awesome feeling to place second!