Anyone that bought the initial release of Avatar, knowing that they announced the double-dip before they released the bare bones, you deserve what you get.
Any "rebate" or coupon on the CE for those that purchased the initial release, it was never confirmed, so there was no point to buy the initial release.
Yes, they double-dipped. Though, they did tell you about it without question well in advance of you to make your purchasing decisions, which isn't something most companies will do.
Mine was under $22 from Amazon, with the $5 discount for purchasing another title at the same time. Most of the discount went to Avatar, so it was around $21.50 and the $14.99 title with it was around $13.50.