That's rather flawed logic, other than the fact that the airline who is leasing out the plane gets to pay for maint, sometimes you'll end up paying more in leasing than the plane is worth in the end.
Have to disagree. The point is not how much you pay for the lease but how much you get from it. Let me try to explain with an example:
Plane model X costs €2,500,000 and you can lease it for €500,000 per month (very expensive, but so be it). It brings €50,000 operational profit per day. Assuming you have the required €2.5M, you can either buy one single aircraft or lease 5 of them. At the end of the month, your single a/c made you €1.2M. Not bad. Had you leased 5 a/c instead, you'll have 5 x 24 x €50K = €6M. After paying the rent (5 x €0.5M = €2.5M), you would still be richer to the tone of €3.5M (6 - 2.5).
In this example, leasing (even at an very expensive rate) would have been by far the best choice.
Now, I don't claim this to be always the case. When you move to more expensive planes, economics sure start to change.
Yes is a really money maker... one of this is running at 183.000€ per day.... is it good?
How good that is depends where you're operating from. But I must say I have planes that cost 30x more than that bringing me less profit. So... yeah, it sounds good to me!
I still disagree a huge part, maybe the guys over in the larger areas that are not very swamped may be able to get a lot from it, I have seen airline who leased a huge fleet of 737s just go down quickly as they made the assumption that "hey, I operate the 737, I should earn a million right now" without realizing that they still have to pay off a lease, gate costs, crews (which I recall the airline who is leasing in still has to pay for), which still, if the airline leasing out is smart, should cover their maint costs and then some more, a nice rift in your own DOP. As for the maint rising part when you own? Again, I find that it pays off to make sure you keep your fleet up to date, not to mention that new planes get introduced that can make more, so it gives an incentive. Some aircraft (like the cheaper ones) are possibly worth leasing, but larger ones are definitely not worth it in my opinion. Operating from small markets, I can tell you that small market airlines have to own or else their profits would be considerably smaller than ones who own, unless that leasing airline has a good friend in the game, at which they could lease them in for a lower rate than the market ones typically are.