I second what Chuck said. Most woods that have some figure or interesting grain, like crotch sections where two branches come together, will often get snatched up. Plain, straight grain wood not as often but if it's truly straight and blemish free it often will still get interest. Stuff with cracks, knots, rot, etc have a limited market, mostly to people who either stabilize and / or cast with epoxy. So you're probably going to have to open those logs up to see what's inside. If you really have some old growth redwood that would certainly be worth milling.
