I think perhaps you misread what I wrote?
Pay special attention to this line:
You can grab a couple of open box 270x cards within your budget and they will outperform everything else listed in the budget so far.
I was talking about getting 2 of them and running them in crossfire.
So yes, running two of them in crossfire would very much out perform a single 280x or 770, which are the best performing cards mentioned, as of yet, in the OP's $350 budget.
A 780, which ISN'T currently in the budget, would still be very similar in performance. Remember the article not long ago about 2 660's out performing a titan in many games? The 7870 and 660 are very similar in performance. Trading blows with each other. The 7870 will even beat the 660ti in some cases.
So, in short answer, no. I am not trolling. Just using my previous experience with all of the cards listed (except a titan) to help the OP out.