Well I did some experimenting and concluded that Product Price Manager isn't working with this pre 1.3 version. I finally learned how to do attributes, and found the problem others have mentioned, that is I see a 0 unless logged in (or was it logged out, can't remember).
But as I said, I have just a few items that have quantity needs, so......
I just created a new category, with my quantity discounted products duplicated in this area. And used no attributes. Then I put a minimum quantity in for each one, such as 15. and the retail and a wholesale price. If someone is not wholesale authorized they will not see the discount. When logged in, all is good. And my other products can also be selective wholesale. Neat.
Now what would be a cool option is if the retail price could be set to "Call for Price", but when I tried that it would not allow a checkout for the wholesale either.
That answer may be here;
http://www.zen-cart.com/forum/showthread.php?t=39487
but I need a break.