I suspect you've probably got it about right. I think the big retailer buying power factor is at work here.

Huge retailers can negotiate with sellers for very favorable terms in return for buying huge numbers of bikes. Sales people cut their commissions and manufacturers cut their percentage margin and make up the difference with big volume. WalMart is known for doing that. Sometimes, it doesn't work so well in subsequent years. Sales quotas tend to be based on last year's sales so, the manufacturer's rep gets put in a real bind. If he doesn't grant even more concessions, he risks not getting the huge order and, consequently, failing to meet his sales quota.