No "mainstream" console ever is a bargain at release anymore. The games everyone want don't come out until much later in the console's lifespan, so people who get these consoles right away have either a lot of dough to spare or a very specific reason to want them.
That being said, marketing...
This is a very nice explanation of Punch-Out!! Factoids.
Hrm... my favorite probably has to be Aran Ryan in the Wii version. I like his character, I also like the most effective strategy to fighting him. I'd say King Hippo is probably more iconic?