Regarding Gunbroker values, asking prices are not the same as selling prices. To find a relative value, do an advanced search on GB to see which guns actually sold, and how much they sold for.
"Asking" prices mean nothing if there are no bids on them; I could put a $500.00 gun on GB with a $5,000.00 asking price, which would not reflect the actual market value of the gun, but someone would see it and assume their identical gun was worth 5 grand, even though nobody in their right mind would pay that. In fact, many sellers do just that, and, with GB's automatic turnover feature, have guns listed with fantasy prices for months or even years with no bids. They are just wasting Gunbroker's bandwidth, but some people never learn.
SaxonPig hit it on the nose. "List it on Gunbroiker with a penny starting price and you'll find out exactly what it's worth." (I.e. what someone is willing to pay for it.)
Unfortunately, the cold blue is going to cause a substantial reduction in what you are going to get for that gun. Cold blue leaves a very unappealling grayish mottling on the surface of the metal after it starts to wear.
