Boat dealer "base" price

A buddy of mine priced out a certain make/model boat a few months ago and then I recently had the same dealer build me a boat as well (we both have bought boats from this dealer before) and when looking at the build sheet our "base" price for the same boat is exact to the penny. I've seen a couple build sheets of the same year/make/model boat from dealers in different states and their "base" price is anywhere from $1000 to $2000 cheaper. The option prices were off some, but not enough to worry about...$5-$25 here and there on the little stuff but a few hundred off in price difference in trailer bling and stereo packages. I know my dealer is one of the top dealers in this brand and the other cheaper base price dealer is also a major dealer. Do dealers set their own base price based on volume discounts possibly from manufacturer or is it just up to each dealer to set their own "base"...maybe a combo of both?