Like I said, part of the cost was getting ahead of the market.
As far as other options to shed upwards of 3 Mil. Im not sure there were any. You suggest Maatta was a better choice. Maybe, but again, you're failing to acknowledge that Yzerman clearly valued Walman less. This is evident by the fact Walman was scratched down the stretch and Maatta was not. So yes, there was an element of "I gotta get rid of this guy, now" it was not, however, a situation where Yzerman called the first GM in his contact list and accepted the first deal that was offered to him.
Look, when the trade broke, I found it quite jarring. Flatly I was stunned and annoyed at the cost of this move for a week but when you step back and look at this objectively, Walman clearly did not have value to the red wings or other GMs. It sucks, but it is what it is.