"The ones I quoted are 100% private, mine is private, you could lower the already low cost by sharing if you wish, worth reading the link I provided."
Yes, sorry, I wasn't clear (and that I can't figure out how to quote now...). The ones you posted are private (though I guess you could share). I meant when you book a tour on your own, it often isn't just you, so if you want that flexibility, then you need to make sure you are booking an actual private tour. Just because it is non-
DCL, doesn't mean it is just you. We've had "private" private tours that were just our family and private tours that were private in the sense of smaller, but not just us, so just that people should be careful of the fine print when they look at things if that is what they are wanting. I was rather surprised one time to find that our private tour included two other families in a minibus when I read the tour as a private vehicle tour. My fault for not checking more closely, but anyways.
As for a DCL bus turning around for just you, no, of course not. As I said, the family went back to the ship on their own, though the guide helped arrange something. I'm assuming a cab of some kind, though I don't know. Just that in the unlikely event that I was on a tour and needed to get back to my child, then the cost of a cab is not really a factor in my thought process. Maybe it is for some. I was more concerned with DCL being able to find me. Honestly, that's my biggest worry. It sounds like it is different for concierge guests, and that's great, but for most people, about all you can do is leave contact info with GS and hope for the best. I've had great experiences at GS and not so great, so maybe that influences my thought process. I would not personally be comfortable with giving them that info and hoping for the best in the event of an emergency. Just me. Others, I'm sure, do their own thing all the time and have no problem. No right or wrong, just what people are comfortable with.
For airfare, try skyscanner. That's a great way to track prices.
I called 
