I've basically tried to create an economy within minecraft. Paper is the standard currency, with a value of $1, and the other forms are: flint ($.25), iron ($5), gold ($25) and diamond ($50). Using these cost assumptions, I built a workbok in Excel that calculates the "cost" of just about every item or block in the game, with additional costs for crafting, rarity and hazard to obtain.
Items such as logs and cobblestone are priced by calculating the approximate deprecation of the tool used to mine them. For example, an iron pick has 3 ingots, so it is $15 (not counting the sticks or the crafting fee). An iron pick mines 250 (more or less) blocks of stone, so the cost of cobblestone is $15/250. For the purposes of simplifying things, I based all my costs on using iron tools since they are the most common.
Then I set up various "businesses" in my map that have different specialties(e.g. lumber yard, mining company, blacksmith, bank, etc.). If you want to cheat, you can also create one entity to hack resources into. This can be particularly useful in providing currency, if you want to operate a currency based economy rather than figuring out how many blocks of dirt equal a pickaxe.
I've even added parts to the workbook that can calculate the estimated "cost" and revenue of a mine, based on what kind of a mine and how big it is. At the very least, it's useful for estimating how many tools it'll use and how many chests will be needed to hold all of the materials.
That's the simple version of it all. I've put WAY too much time and thought into all of it, but isn't that the nature of a hobby?