You may not be able to buy Festool cheaper at retail, but if you keep your eyes open there are deals out there for Festool on Craigslist/Kijiji.
As for the rails specifically, I'd look at the Makita rails. I picked up the 118" for $120 used on Kijiji - it was like new and it came with the carrying case. Even at full retail though, my dealer sells the Makita rail for less than half the equivalent Festool. Though I understand they may not work with the full range of Festool accessories, my TS 55 certainly works fine with it- in fact it feels like it grips the work piece better than my Festool rails.