Not really 35% off. That "sale" price is within a buck or so of Rockler's (non-sale) price and it appears that from some of the reviews, they're filling the orders through Rockler anyhow.
I think it depends on what blades you are looking at. I picked up the Box Joint cutter set for about $25 less than Rockler. That may not be quite 35% off, but with free shipping not a bad deal.