W5 Heads for sale.. how much are they worth?

Over the years I've seen guys that port heads complain about issues with the W-5. The material some were cast from is very brittle and don't weld well or at all if repairs are needed. Porosity in the castings and core shift making a cnc porting program very difficult because what works on one head will find water in another. As mentioned when a good set is found in the right hands they will make good power.