1. You'll never find Hermes ties at a mass market discounter, such as Century 21 or Filene's.
2. Hermes runs a winter and summer sale off-premises at either the Metropolitan Pavillion or the Alliance Francaise. Ties are about $90-99. Check the NY Times weekday editions for the balance of January and February on either pages 2, 3, 4, or 5. Lines can be long and daunting, such as an hour to get inside. The best bet is to go at the end of the day on either Saturday or Sunday, however, much of the good stuff will be sold by then.
3. Sometimes a retailer will place its Hermes ties on sale. E.g., this last summer Hermes sale ties were $79 at Bergdorf. I haven't seen any Hermes ties on sale during this Winter season.