I believe the markup is 100%, because that puts the shop making much less than 40% profit once all costs are figured into price. Trust me there are many more "costs" involved than just shipping and utilities.
Once you figure in "daily incidentials", you would be amazed at how much money a local quilt shop DOESN'T make. Unless that shop has BUYING customers inside from the time they open to the time they close, that shop ain't makin as much money as you think.
I AM NOT A SHOP OWNER, but I have been a business owner (not quilt related) in the past.