I think there was a problem with the website this morning. When I got up, I checked it to see if the 600 R-T was back in stock. They showed that almost everything was back in stock, but no sale prices.
Then, a half-hour later, the sale prices were back but the strobes (and most other items) were listed as sold out.
I guess I got lucky, because yesterday morning I ordered two 600 R-Ts. I got a confirmation e-mail and so far, no cancellation. I wanted to order four, but also wanted to break the order up in order to maximize the savings. I got two ordered and then when I went to order the next two, they were sold out. I'll just have to wait until the next time.
I'm always a little suspicious of how Canon USA handles the refurbished sales. For weeks before a sale, they will have a product in stock and then as soon as the sale starts, things are immediately out of stock. Then the sale ends and suddenly products are back in stock again.
On the other hand, the prices are so good and the sales so frequent that I really can't complain too much even if they are manipulating their stock levels, which I strongly suspect they are.