I doubt you will find a retailer that would offer a Surly at less than msrp; they have a pretty strong and well-protected brand. Your only chance of a discount I think would be if you can find a place that's clearing out old models because Surly came out with a new model. That said, for $1500 it's a good value. The fact that other bikes can be had at discount so readily, says that they are overpriced -- there's a margin built in to allow for frequent discounting.
Again though, take a look at the Surly/Salsa facebook group to see what the used market looks like.