But they don't seem to depreciate that much. Most Cessnas and Pipers have a higher price today than they had new, if kept after.
That is true for perhaps any plane IF it was bought long enough ago - say 30+ years ago.
Of course the reason for this is that vastly more money (than its value) was spent on maintenance in the meantime, which nobody would do with a car unless it is a rare vintage type.
It also used to be true that new price inflation would protect your depreciation. This I think was the case for many years. I have not been flying that long but for example I bought a new plane in 2002. In 2003 the same plane was listed at 10% more (I checked for hull insurance purposes).
In those days everybody thought this would continue, because it had (at the time) continued for many years.
But c. 2005 the bottom fell out of the market.
Now, 7 years later, my plane would sell for about 70% of what I paid for it and believe me this is a
damn good price relative to most others. Only a few other choice items (no longer made, like mine) would fetch that. Most others are down to maybe 50%, and the "popular plastic" ones (e.g. Cirruses) have suffered massively with some being worth maybe 20%. (There was a long thread here on the Cirrus recently).
But if you took out a loan, you will be repaying the full amount
And then if/when you sell, you will have a huge shortfall to fund.
My opinion is that if you have to borrow money to buy the plane, don't buy it, because you can't afford to maintain and operate it after you get it. Buy what you can afford - no more.
I would agree totally, but many UK pilots would jump on you for the first sentence there
because the same argument would be (correctly IMHO) applied to so much else in GA not to mention the rest of one's life, and most people don't like to be told they "can't" do something.
For example if one cannot afford to get one's PPL (in the UK, at UK prices) one will not be doing much (or any) flying afterwards, because the ongoing cost of flying will over many years come to many times the PPL cost.
Anyway, re the purchase price, also allow a margin for mishaps and maintenance suprises. Insurance should cover mishaps but you need to be able to fund stuff like engine rebuilds. I guess that at the C150 ownership level you need to always be able to write a cheque for £10k or so.