NexGen Lending was looking for a way to improve its operating efficiency and pricing capabilities when executives discovered a better way to cull more profits from its secondary-market operations. The Denver-based lender decided to team up with Sollen Technologies, an Internet-based application services provider. This partnership, NexGen officials said, has allowed the lender to improve its marketing capabilities, to streamline its pricing systems, and to bolster the resources available to its sales force in the…