Yeah it's one of those things that can bloat the budget, but if an actor is keeping his schedule open for a film they expect to be in, and they get replaced on a whim, they deserve some financial compensation.

Would be neat if BDW got to voice Two Face in a future DC animated film someday.

When the old gang signs the contracts for Episode VII, it's going to cover a couple more sequels at least. With the exception of Harrison, as he may only be lured back with the promise of dead Han. ;)