There are lots of factors that aren’t getting called out here. We recently reroofed an older house that originally had shake shingle installed on skip boards. To upgrade the roof, we had to have the singles taken off, and OSB board put down to cover the skip boards, then the shingles installed on top of that. The roof was also lots of small sections, not simple large areas. It was a 2000sqft house plus garage. We got a triple layer shingle. All in all, it cost just under $20k. We did a number of bids and that was not the absolute cheapest, but was one of the lower cost bids. We could have lowered the cost by going with a cheaper shingle so if you’re looking for a rock bottom price, don’t use our cost as an estimate.
The company was Premium Roofing, (619) 239-8880 and I highly recommend them.