The Antonovs the primary a/c used in the outsized cargo market because there really is not any other a/c out there that can do the job other than the Airbus Beluga. Right now, the operators of these large a/c can charge what they want because they know they these customers have no other choice. The Antonovs are of military origin, but yet there are no civilian versions of the western equivalents, the C-141 and C-5. The STOL capability means very little to the outsize cargo market, just the ability to get large items to where the need to go. Boeing will have trouble trying to sell the BC
-17 because there is not a market for the a/c, as the demand for a/c capable out handling outsized cargo is being met with little if any delay. There may be an upturn in the demand in a few years, but will Boeing be there to offer the BC
-17? As long as military orders keep coming in for the a/c, it will stay in production. Look how many years the C-130 has been in production, nearing 50 years. There is even a L-100J version of the C-130J, but is not currently being marketed by L-M.