I came across a great deal today at BJ's Wholesale Club. They had a four-pack of Wenger Swiss Gear 32 oz (1L) Lexan bottles for $7.90 before tax. These are very similar to the Nalgene 32 oz. wide mouth bottles that normally go for about $10 each.
The Wenger bottles are about the same diameter as the Nalgenes. The Olicamp Space Saver cups which I got from Campmor fit over the end of a Nalgene will accept a Wenger bottle. However, the mouth on the Wenger is a little larger than the Nalgenes, so replacement caps or water filters designed to fit the latter won't work on the Wengers. For less than 25% the cost of a Nalgene, I can live with this.