I haven't decided yet if I'm going to buy them, but I've spoken with the guy some more. I asked him if he used them, and how did or do they work. He says he tried them a few times many years ago (he's had them for 30+ years), but found it difficult (I had asked him if they were particularly hard planes to use). He says, though, that the planes are as sharp as ever and fully functional, and in excellent condition.
I would not base a decision on such a set based on a person who may not know how to sharpen blades that are not square and may not know how to set a blade in a wooden plane.
If you can try before you buy, that would be the best way to make up your mind.
I would buy them and try them at home. At that price you could likely sell them for as much or better than your paying for them on ebay.
jtk
"A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
- Sir Winston Churchill (1874-1965)