If you can sell a $100 miner to the public for $500 why not?  Then you can take the $500 in revenue and buy 5 of your own in-house miners and the net result would be 6 units added to the network at the cost of 1 to the miner company.  The miner company would get 500% the hash/$ as you do and have minimal downside with increasing difficulty.

If they didn't have plans to do so now they do