I think it is possible:
If there would be So many ASICs sold that difficulty will increase 200x then:
650$ cost BFL ASIC will give just 17$ per month so 38 months to refund tool, if you want add electricity and financial cost.
In this case I think that lots of ppl will think: "If I have to wait 4 years to start earning, I'll cash ASICs now and quit (like pope now:)) .
Then they will have to sell ASICs cheaper
ehh how edge profitably mining is nowadays
there is 1000th sold already
so im not sure wat u askin
at 1000th u will make 2 btc a day with a 30k minirig
ofcourse thats till nwtwork grows to 1200 1500 2000 etc:)