^kanzenban volumes are likely to not be released until One Piece is finished…ie like twenty years from now. I don't know if they'll make exceptions for series that have been running for like 20 - 30 years considering OP is currently on it's 14th year and most likely no more than halfway finished (and given Oda's tendency to make everything longer, I think less than that).
Now, I was thinking about it...this "trying to save the fans money" by not putting a few extra chapters in a volume is sort of a fallacy. The logic just isn't correct.
If Oda had gone up to 597 in volume 60, fans would get about a 30% increase in page number for only 7% increase in price (judging by the pricing of Naruto volume 43 vs. all other Naruto volumes). Furthermore, if he puts less chapters in the volumes, fans by more overall 420 yen volumes in total...meaning more volumes for Oda that sell 100 million copies at the full 420 yen price. I'm not saying this is his intention, but is what will end up happening. Those 3 extra chapters would add up. Every time he goes up to 12 - 13 chapters, the price goes up 30 yen overall. However, this also means 3 more chapters put into volumes. 30 yen times 3 would be about 9 chapters...enough for a full extra volume. Instead of making 90 yen on those chapters, he will make a full 420 yen on them. (not Oda, the publishers). Again, I don't think this is what Oda INTENDS, just what will end up happening.
I don't think he should put that many chapters in a volume each time by the way, just that he shouldn't worry at all about going a little over if it's better for the story.
In this case 597 was by far the best way to end volume 60. Chapter 594 was also a semi-decent way. 595 is just terrible. Separating Sanji and Chopper's moments from the rest of the crew? Lame. 595 - 597 needed to stay together...even if they were overflow into volume 61.
I really think Oda is just the worst in terms of volume endings though. Same as with volume 45, volume 43, volume 52, etc. Though this one is probably the worst in my opinion. Didn't care so much about the others, just thought they were a little off. This is kind of...bad though =/