The answer to this might be found in some research from Vintage Computing and Gaming website. They recently took up the challenge of comparing the price of VC games against the current eBay average ending prices. Generally speaking most NES games can be bought used for peanuts now so the savings aren’t so great except for a few rarer games such as Bubble Bobble which might sell for $20.
The contrast becomes much more severe when considering TurboGrafx-16 games. Some games like Bonk 3 are so uber rare they will cost you $200 on eBay compared to the $6 Virtual Console price of admission.
Across all the games currently on the North American Wii Shop it was found that you could on average save around 50% on the eBay price by buying the VC version instead. Of course with the Virtual Console you can’t just sell the games on if you get bored of them, but if you pick wisely to begin then this isn't really such a big problem.
Of course there are those of us who just love blowing into their dusty NES cartridge slot and playing the original carts, hey we can’t blame you – nostalgia is a powerful force! Still for those who just want to play the games this seems like positive reinforcement that we are not getting such a bad deal on the VC after all.