Salary, what am I worth?

I currently work at non-profit buying co-operative in the lumber and building materials industry. We are amongst the top three companies in the industry but only staff about 50-80 people at a given time. I am a commodity lumber trader currently with a salary of 64K. I hold an MBA degree from a fairly well known regional school. I have been offered a middle management position of my group (6 people). Our group is budgeted for 100 million in annual sales. The offer is for 74K a 10k increase with the promotion. The median compensation for this grade level is supposed to be around 76K. This is a very small industry that serves millions of people but acts like a fraternity. To put it into further perspective I know the VP's make around 150 and the pres near 300K. I would report directly to the VP. What am I worth???