Supergo online has cheap prices right now on DuraAce chains. Just go in the store and have them give you the online price.
Or, Performance is clearing out there SRAM and Shimano chains.
The DA or Ult shimano chains are really nice. Use a SRAM powerlink with it, and you'll have a great strong chain that you can take off easily, as well as you don't have to mess with Shimano's weird special pins. If you DONT use a powerlink, make sure you read the directions carefully on the DIRECTION of how the links need to go back together for the Shimano chains. If you don't follow them, you'll likely break the chain in short order. I learned the hard way, several times.