Yeah, if you're printing both MK and PK you should be fine. Saving up to run sets is the way to go, just don't save up for too long :-)
Good to know - will just have to keep the balance in mind I guess!
As to the cost? That obviously changes for each user, but generally ink is one of the smaller cost components of producing prints (compared to media, time, capital equipment and so on). Not wasting ink and money - definitely important - but needs to be kept in perspective of the overall costs (where there may be other areas for savings).
Very true, it's just that I've got a decent handle on the other variables as they haven't changed much from the older printer (uses the same paper, and the workflow is basically identical). This printer uses ink in a very different way than it's predecessor (tubes vs direct mount, much bigger cartridges, lower per-mL cost, etc.) and it happened to do this while I was still in the process of characterizing it's performance so I'm paying a bit more attention to the details right now than I will in the long run. Ink is a somewhat complex animal in that it takes a bit more of a strategic approach to managing costs, but you are correct that it is certainly not the largest component in the equation. Just a matter of nailing down some best practices and getting some general numbers for the long term, and once that's done things get a lot simpler.
Either way, a big thanks to everyone involved here for the insight!