The other thing here is within the Reserve categorie, you have proven and probable, which are valued the same for most companies. However, in the resource category, you have measured and indicated and inferred. Most people value measured and indicated as the same but the inferred category has less strict criterias and as such are discounted. I have seen 25% discount on a number of occasions but I am sure this varies considerable. So to give average numbers, and these are highly variable, you can use $100 per ounce for reserves, $60 for M&I resource ounces and $45 for inferred resource ounces.
Factors that influence this is:
Grade of ore
open pit vs underground
jurisdiction
management
Price of Gold
Stage of exploration\development ie Scoping study, PEA, Bankable feasibilitystudy
Native issues
potential for finding more ore
Glorieux