I have a similar story. Larger Charter/Management Co's have been calling us for quotes in our "Light jets" that we Own & Operate. They take our quotes to their "Midsize" owners and tell them that this is the price that they need to compete with in order to get the flight. Their owners want income of any variety, even at a loss at times, so the owners say okay to the flight. The Managment Co's are letting their Owners take the hit.
I always figured that the "entry level" Charter jets, such as a Learjet, would always be busy, I have found just the opposite. The larger aircraft has the ability to fill the shoes of the smaller jet, but the smaller jet cannot fill the shoes of the larger.