I would say that's exactly the case: because every batch coming onto the market, will create a rise in difficulty making mining less efficient, and this will apply even more the latter you get your miner. In that tenor I would exspect, that for the asic developers it's a really big buisness, just by "testing" there devices and selling them. I dont want to say that you won't earn money with your device then, but at least without an intensive investment of money you wont be able to skip working, sit back, relax and let your miner printing money. At the moment it seems at least to me more efficient to mine alternative crypo coins and hope for a possible increase in value, than buying a asic miner for bitcoins.