Suggest two changes to the conversion rate:
80 Stone -> 15 Flint (Don't know for other but for me stone was always more worth than flint, so i would here go in a value like 100+)
80 Hide -> 15 Pelt (After you tame your first Rex, you don't know what to do with all the hide, I had it everywhere lying around, even overcome a bronto with and keep throwing it away, but Pelt was always missing when i needed it so in this case i would go for much more Hide for the 15 Pelt)

Can you add dlc resources please, like stone to sand?

How about If you have charcoil you can make gun powder with it