The NRA Blue Book Of Gun Values ( current edition) will give you realistic values for most guns in the USA and have very useful information on grading for condition and how this affects these values. Generally these values need to be adjusted for Canadian value and will vary greatly depending on the class of firearm. I use this book value, listed prices at as many dealers as possible in both Canada and the US, gun show prices, anything I can get to find a reasonable average price here. On used guns if you are not using a recognized grading standard such as the NRA then you are not even speaking the same laguage as potential buyers or sellers. And if you include sentimental value for grampas old gun, pejudice for or against a particular make or model or just your own experience with a particular class of gun then you are not being realistic, you are out to lunch. If you are a seller and really want to sell the item then price it attractively to sell. If you aren't in a hurry but want to get the most return then price it in the top third of similar guns. If you are one of those " I don't really want to let this go but if somebody wants it bad enough to pay me my price( usually well over realistic market value) I'll part with it" kind of guy you will likely have it for a long long time..... many guns on EE being bumped time and again, for months. Remember, the true value has not been established until the gun is sold. That selling price is the true value for that item on that day in that place. Anything else is wishful thinking or speculation.