1) Kids love Bumblebee, which is why they pack so many in. Three Bumblebees in wave 1, three in Wave 2. According to Hasbro, he's far and away kids favorite character, they can't get enough of him.
It's true - the kid market is still far bigger than the collector market.
One piece of anecdotal evidence - when Amazon was running deep discounts on KREO sets around Christmas time, the only set that was sold out prior (and thus was selling for above retail price) was Bumblebee.