Buick 300 alloy heads

[Blown v8]

I have a good set of the above heads,stripped and cleaned,
I have bought new valves Ferrara 1.775 inlet 1.5 exhaust
New springs(crane) caps,retainers,I've even got the seals,
Due to a change of plan,I'm not going to get these heads finished,
My question is,what are they worth ?
I bought them on here,and really would like to sell them on here,but just need a guideline price to put them up for sale,
Thanks for reading