$8 seems like a lot for straight ports, or maybe I am just cheap.
Prices are too high and they need to just unload them all at once. People will keep coming back to the well regardless. No one is going to buy a Wii U based on these releases so doing it over time doesn't make sense. They can't replace the need for an actual, new game release.. they're supplements. Put up 20-50 games at once. People will buy them and/or play them on their own time.