I got an email from him. Tom and Leslie are right -- the sold-out signs on all of their Irises was their way of ending the ordering season. But he told me that there are many of those Irises that will be in the sale, plus many others not currently on their website (maybe the older varieties you mentioned Leslie?).
And yes -- it is an open sale at their place of business. He recommended that I get there early (opens at 8:00 AM) to get the best selection. As it is over two hours to drive there, I can't be there early. And -- looking at their prices, which are very reasonable -- I'm thinking I would just skip this and order from them next spring. They have several Irises I would love to have -- but it doesn't make a lot of sense to get up at 0-dark hundred, drive for hours, spend sixty bucks on gas to MAYBE get the Irises I want and save three or four dollars on each one.