David: Do you use color or don't you? If you do, it was made in an inefficient furnace 4-10,000 miles away and sells for up to 55 dollars a KG. Thta's inefficiency.
I make five gather pieces a lot. If I were to use a 100 lb melter I would charge every day or every other day, and at 2150 if would take forever to fine out. The cost of running a furnace is during the charging time, not the idling time. My electric bill would probably actually be higher than it is with the current moly unit, based on high fires.
Further, pot life is based on the same cycles. Your pot is good for 70-90 cycles and should be replaced, invested or not if you want great glass quality. At my current usage I would pull the pot every two months. That is not attractive.
What works for you is due to your scale of operation, not the genius of the design.