My opinion (for what it's worth) and to coin a phrase my old nan used to use, 'God helps those who help themselves'. Which in this case I use to mean if you really want to buy a top drawer classic vehicle of any make and ensure that you are not being ripped off and buying a lemon, then you HAVE to do the hard miles and research your subject.
If you are prepared to do this, and ask lots of questions, research books, speak with people on forums etc. then over time you will build yourself enough knowledge to ensure you know what you are looking at in the vast majority of cases.
Lets put the issue of money aside, if you have the funds and want to buy the vehicle, then you are going to do so. Where it usually goes wrong is that buyers go about things the wrong way around. They save up over a long period or are lucky to have the money come available and they suddenly see what they think is the perfect vehicle and rush into buying it.
What they should do, is during the period they are saving up they should do their homework/research, so that when the money is eventually available they have the knowledge to make a wise purchase.
More difficult is when the money suddenly becomes available, they don't have the patience to wait until they build their knowledge, leaving the money in the bank until they are ready.
I myself was a good example of the former. Many years ago at the ripe old age of 22 I decided that I HAD to own a 101 Forward Control. However, I had no money. So I started to save, bit by bit. At the beginning of this process, I joined the 101 club, researched lots of books and attended lots of club events and spoke to lots of owners and pored over their vehicles at shows. I attended the military auctions where they were sold, learned what made a 'good one' and what didn't.
After three years of saving (and more importantly learning), I finally got my finances in a position to afford what I now knew 'good ones' sold for. At that time there were still some being released through military auctions, so that is where I looked and found an extremely good example, of the most sought after spec. and bought it, safe in the knowledge that I knew what I was looking at.
27 years later, I still own the vehicle, which is extremely original, never been welded and is probably worth in excess of 10 times what I paid for it.
The title of this topic is therefore correct. Most people, when they have the money do not apply the sense. If they did, they would take their time, learn their subject and buy when they are sufficiently educated to make a knowledgeable decision.
Ian