Good idea, @Kathroman
I think the weighting might be more effective if used as an average. (EDIT: Just realized that mathematically, your notation is exactly the same as mine just after the distributive property) This example would give you a price that is 30% influenced by AvgBuy, 60% by DBmarket and 10% by DBMinBuyout:
(3*AvgBuy + 6*DBMarket + 1*DBMinBuyout)/10
Or, you could try to work in a Min() as a fallback to AvgBuy so that if the DBMinBuyout is less than your AvgBuy, it will use that instead:
Or come up with a fancy combination of the two (or anything else you might want) with something like:
(3*Min(AvgBuy, DBMinBuyout) + 2*Min(DBMarket, wowuctionMarket))/5
P.S. Don't forget to add your coefficients correctly to get the right denominator. This is why I put "1*" when I do weighted averages, so it's easy to see what the denominator should be. Having a denominator off by one number can greatly skew the equation to wildly inaccurate values.