It is hard to figure prices, it all depends on the Metrics,
If all is well then they can be on road for 100,000 ounces a year, given the current tax structure, you are looking at roughtly 500$ in their pocket per ounce (this is conservative) and that means 1.1$ per share from this property.
If you give them 5-10 times earning + value for other projects .. you could be wildely between 6-13.
Now if they drill up Zaroma and increase the size you get a different matrix
you can get from 100-250$ per production ounces in the ground and getting 3-4 million ounce in production would put the company in the high teen digits without any other property.
So the factors are
1 - Production Rate
2 - Exploration
3- The Ecuador discount.