I have a Johnston Murphy belt that is a close match to the AE Walnut. I got it at a local store for $49.99.
+1 for Johnston Murphy. Also check Jos. A. Banks. Both of them sell belts in colors that are very close matches to AE's "walnut" at substantially lower prices. (I own a pair of AE Fairfax in walnut and pair them with a JAB belt that is all but indistinguishable in color.)