Bitcoin price is not tied to computational effort spent on mining. The creation rate of new Bitcoins is already constrained and well defined. Producing more machines would just mean Avalon would get a larger portion of the new Bitcoins.
This is a very unhealthy thing for the BTC market in general as only a few players will have the ASICs to mine profitably, and everyone else will be spending far too much per kW to do any mining at all.
One of the weaknesses of BTC, as far as I understand, is that anyone with a majority of the global hashing power can rewrite new transactions on the blockchain. If regular GPU miners give up and a few players spin up some massive ASICs, we may very well see this become a reality.
If they're that good and the manufacturers put a load online themselves, then the folks buying one are not buying as big a slice of the pie as they thought they could?