Last week, Nintendo announced that they will be hosting a character specific sale on the 3DS and Wii U eShop from now until the end of the year. Many Zelda games were on sale last week.
From now until Nov 29, 2013, a few Mega Man games (NES) will be discounted on the 3DS eShop:
Mega Man – $3.49 (normally $4.99)
Mega Man 2 – $3.49 (normally $4.99)
Mega Man 3 – $3.49 (normally $4.99)
Mega Man 4 – $3.49 (normally $4.99)
Mario games are scheduled to be on sale started the week of Nov 28th with Donkey Kong games to follow after that.