Edit: Since you edited, I'll be fair and explain why you are still worthy of a facepalm by saying "let's look at how a $330 Radeon R9 390 is almost running like a $550 R9 290X! How can AMD do this to its users? How???"
280X and 780 Ti launched within less than a month of each other, at $300 and $700, respectively. These cards were contemporary competitors at those prices. The latter card is 9% faster in the graph you linked. A bit of an error when seph1roth said Look that 780Ti, a 600$ GPU running almost like a 250$ GPU from AMD. He was off by prices, but the ratio of prices is nearly correct to what he said.
The 390 for $330 launched nearly 2 years after the $550 290X. How utterly misleading. It also stands strong above its equal priced competitor, the 970. And, btw, that $550 290X was competing against the $700 780 Ti at that time too and now the cheaper card is 28% faster. Taking 290X or 390 price or performance in this game this as a negative reeks of desperation and is just off base with reality.