Dangerboy, a long time contributor to DP, has put up a great video showing how VGA is nothing more than a pyramid scheme, and does nothing to actually perserve games.

http://www.youtube.com/watch?v=1BbHDMXxm04

If you look at VGA auctions, most of them do not sell for any more than a regular sealed copy of the game, let alone the $100+ extra it takes to actually grade the game. If you look at the supplemental video, it also shows how easy it is to create a fake misprint, something that VGA actually graded. Also shown in the video is that the item itself was damaged after being sealed in the case, proving that the cases do not actually provide full protection for the game.

And let's face it, people who use VGA are not interested in preservation. Take this auction of a NES prototype. The seller explicitly states that the ROM image of the prototype has not been dumped. How can you justify sealling up a prototype without dumping the binary? The memory on EPROMs do not last forever, especially when they are allowed to be exposed to open light like they are in this auction.