That would only be 125k in sales per game. If you take four popular games and give them about a year for sales, who knows what can happen. The real key will be the rabbits having some big box shelf space and making a name for themselves on the educational sites.
The best part is that rabbits should be a steady money maker for the next couple of years. We also have what looks to be the re-release of the Kindergarten DS game and others on the way..