One problem I'm coming up with is in my strategy game there's 3 races to be, and you start a town and the #1 most fundamental resource is money, with food being just as good since it can be sold to the market for money.

I wanted to make these 3 races unique by giving one race the ability to produce large amounts of money, and less food, and another race by allowing them to produce lots of food but less money, the problem with this is there's an illusion of diversity, since food can be sold for money at the same rate.

So I thought, why not change the market prices so often?

so if you had a low price and a high price for food that changes every so often, how would you balance this out?

better example:

one race produces 1000 money but 250 food
the other produces 500 money but 500 food

normally food could be sold for 2 money per food unit

but with a market rate change, the prices jumps from 1.7-2.3 (or inbetween)

Also, does this still just seem like an illusion of diversity or is it actually making the game more unique?