I said this right away, but no one paid attention
Not only is the change fee ridiculous, the redeposit fee, which is the same, is even MORE ridiculous.
If I have to cancel a trip, CO is probably not going to put that seat back into award inventory and instead, sell it. I'm actually earning CO money by cancelling. I understand there may be times that seat is not sold, but it certainly can't cost them $150 to press a button to give me back the miles.
I am not making award reservations for my parents specifically because I can never ever get the dates I need and always have to either change or redeposit. I refuse to pay $150 to do either, so I'm just not booking.