At this stage, it may be the same cost to the network no matter which group of episodes they license. Previously, I would have said it would be cheaper to just license the tapes they already have, eliminating the dubbing process. But now that they've presumably (yes, I know I'm presuming) moved away from tapes to something more modern, there's likely a dub session no matter what.
That said, I'll be happy no matter which part of the run these are from.