I should pat my vendor on the back, lol. We already had the network infrastructure in place for VMware, and we told them we wanted a SAN, our sales rep made sure we got two SAN units as soon as we started talking about failover stuff... Or maybe he was intentionally overselling. (I saw your blog post about that, lol).
If you told him you wanted the SAN and he came back with "you need two of them" then yes, pat him on the back. He didn't conjure up a miracle or anything, he made two high margin sales there. But he took the risk of telling you to "go high or go home" instead of trying to sell you one "sure thing" SAN and pass the risk off to you. He probably made out like a bandit on the sale, so you shouldn't feel obligated to buy him a ham for Christmas, but he did the right thing and that's unusual.