I think you must try to think about the comparison of the antminer and profitability with other like GPU mine, as you can see about the fact i think that the antminer would be more profitable rather than gpu mining for ethereum, but i kinda feel disappointed for the electricity consume.
But with the next update from the ethereum developer to put the difficulty bomb to complete the pos migration and it might be a best choice to buy antminer rather than build your own GPU mine.