Actually none of those games are sealed, i'm actually quite surprised someone would be that easily tricked by Air Zonk, considering it's just one of those game protector wrappers with an adhesive seal. Monster lair is not only not sealed, but I bought the disc/plastic case from Jello here, and the box itself from someone else. It does however have shrink wrap around the box, so I could see being confused. None of them are sealed though, whoever sold them to the people I bought them from just kept the wrapper on. The Splatterhouse coming my way also has the shrink wrap, but is not sealed. I'd be shocked if most people here don't have something like that.
I believe on TG16, I only own a few sealed titles out of the 90 I have, and they were sold at a fair, used price. Keep on trying though, for real. I don't buy new games though, not unless the price is the same as used, simply because I don't want to destroy the supposed value because i decided to open it.
It's a shame people here make so many assumptions without even asking, I spent a couple hours and about 80 bucks modding Atari 5200 controllers yesterday so that I can play the system, I feel I go quite an extensive length to make sure all my stuff can be played, but then someone here diminishes all that because they spotted shrink wrap.