The value of a custom (or customized) rifle depends a lot on who sees it, wants it, and weather they have money to spend. Your estimate is reasonable but if you really want to know what it's worth sell it on GunBroker.com Online Gun Auction
. Thousands of potentiall buyers will see it, but they'll also see thousands of other rifles for sale. Selling at a gunshow can get you a goodt price with little overhead (shipping & ffl charges) if you have time to walk around showing to people. The price someone tells you on the net without even seeing it doesn't mean much, nor do Blue Book prices.