You have sound advice, except that to go the vintage Stanley route assumes that the person asking for advice:
1. Has some idea of what a well tuned plane can do
2. Knows how to set up and tune up a used plane, and
3. Knows what fatal flaws to avoid when purchasing a used plane.
My guess is that in almost every case, the person asking "What should I get for my first plane?" doesn't fit any of the above three items. That's why my usual answer to "What's the first plane I should get?" is "Take a class on using hand planes and sharpening, or find a local woodworking club and look for the hand tool guy." This is the sort of thing that I've found makes a much larger impact in person than on the internet.
For those people who don't have access to either classes or a hand tool maven, a Lie-Nielsen or Lee Valley plane may be the only hope they have of seeing what a well tuned plane can do.
My first woodworking purchase was a class. Since then, I've only bought used planes. But I also know I needed that hands on instruction experience, or I would have been lost.
If you really want to have people thinking about vintage/used planes, you might want to take this into consideration.