Buying: Wood logs: Oak: 1 Iron per stack; 15 grass per DC Dark Oak: 1 grass per stack; 1 diamond per DC Birch: 1 grass per stack; 2 diamonds per DC Spruce: 1 iron per stack; 1 Diamond per DC Wool: White wool: 2 iron per stack; 1 diamond per DC
1 DC = 54 stacks As 54 Iron is 84.4% of a stack, and 1 stack = 1 dia. 1 dia =20-25 Grass Therefore 1DC by your prices should be between 17-21 Grass. Therefore I would make more profit selling you stacks of logs individually then by the DC.