I think if he just got his touches and the team wins he would be fine. Wall could probably keep Cousins in control and if Wall succeeds in that, the Wizards would have themselves a near elite center. If the Kings aren't asking for a (pardon the pun) king's ransom for him, they should go for it since a combo of Wall/Beal/Cousins could be deadly and would be one the best teams in the Eastern Conference. I doubt they're going to ask for TOO much anyway since they probably don't want to give him a max contract and they don't want him around any longer.
I'm still in the camp that the Wizards should tank this season if they start to become plagued by injuries. The 2014 class has too much talent within the first seven or so picks to pass up. This class could end up being a class like 2003. A win total in the mid-thirties or a first round playoff exit really does nothing for them.