The dior outlets are hit-or-miss. for most pieces, it's just the sale price that it was at when it was on sale at the dior store, 50% off retail. occassionally though, there will be pieces that have an additioanl 50% off the already reduced price so usually that's a pretty good deal.
also you can find past-season stuff there, I would say it dates back at least 3 seasons.