You speak the truth, Brother John!
Now, I'll share the following opinion: "pre-buys" are only useful to determine that the aircraft in which you are interested is of sufficient condition to have an Annual Inspection performed by your mechanic/IA (not the seller's, ever) before completing the purchase. There are no, repeat, no standards for a "pre-buy". It is whatever the mechanic wants it to be/not to be, and has no standing under any Reg.
An Annual Inspection, on the other hand, has standards established by/in the Regs. I have had Annual Inspections performed on aircraft that I ended up not buying (saved my tail), and on ones that I did end up buying. I have had Annual Inspections performed on aircraft that had one mere months before, just to be sure that the inspection met known standards. Besides, when I did buy the plane, it was good for a full 12 months.
The point is, once purchased, all the problems/expenses found subsequent to the purchase are mine. A $300 to $600 Annual Inspection is the cheapest way of minimizing the risk. Any noted deficiencies/required repairs/replacements found during that Annual Inspection should be negotiated into the price. I have the right to walk away if the seller will not make those corrections on his dime, or if the deficiencies are too great to overcome.
As I had indicated in a previous post, I know of an expensive airplane purchased on the basis of a paid-for "pre-buy" that was grounded by the same shop one month later for long-term deficiencies found during the then required Annual Inspection. The shop held that the "pre-buy" was not binding, but the Annual Inspection was. The buyer lost in pursuing claims against the shop.
So, count me on the cautious side. A "pre-buy" is a fancy name for someone looking at the plane. It's only function should be to see if there should be a second date - a true inspection by the Regs.
This is my opinion, and I'm sticking to it.
Mike.