So it still seems that 2700 sq. ft. total, and 1600 of that being well insulated, using about 50 lbs. in 2 days was very good. We do plan on finishing the basement hopefully before next winter and will have it well insulated too. But even without insulation, the basement is really toasty, too toasty in fact. We will be getting 2 tons of coal delivered in a week, so we'll save more by not purchasing it in 50 lb. bags, too. The coal place told us that 3 tons should be fine with the Hyfire II and our sq. footage (they are familiar with LL and our stove), and we would probably have some left over at the end of the season. We can only buy 2 tons right now though. After reading everyone's usage, I feel reassured that we're not burning an excessive amount.
Someone mentioned our min setting perhaps being too low. We have a Coaltrol and factory settings were 6 and 40, we lowered to 4 but with max at 40 we had some burning coal being pushed off the grate, so were advised to try lowering max to 38 and see if that fixed the problem. It did!
This stove is so much better than using our woodburner, I'm so glad we switched. No more cutting, carrying firewood, inside mess, filling the stove twice a day with wood, etc. So much better!
Thanks again for your replies, guys!