You must be refering to medicine bow woods...(Dave Roberts) I use to sell him wood Cascara staves, vine maple, figured maples. Any way as to value......there really is very little value when it comes to yew other than a VERY FEW SPECIALTY furniture makers, and wood turners to my knowledge. Use to be a Taxol market(for cancer) that killed tons of yew trees.
Obtaining permits to cut yew is not easy in Wa. I have often wondered how Dave gets so many primo yew staves to sell.......I never asked, and he never told.
As to price.....Seems Daves prices are fair for the effort it takes to find nice yew staves for bow making. You can look at LOTS of trees that are not any good to the bow maker. On the other hand low elevation yew is still yew, and will make a excellent bow.....people have been taught that ring count, and and sap to heart wood ratios the most important thing....this is NOT true all yew will make a fine bow, some is just better quality than others.
One more thing if you look carefully Daves yew staves are sawn not split to my knowledge. Yew is to hard to come by to split in my opinion. I saw all of mine.
Brian