If they can't afford to improve to that level, they don't have any other options.
But thus far no one has been able to answer this question:
If 100% rebrand, why keep delaying the launch of R9 370 - 380X series? Just take R9 270/270X/280/280X/290/290X boxes starting January 1st 2015 and just call them 300 series. How hard it is to put a new sticker on a card? With most of those cards there isn't even a name on the card so it would literally be just putting a new sticker on the back of the PCB and just putting the card into a new box.
These are R9 280/280X cards
These are R9 290/290X cards.
Without checking the power pin count and the sticker on the back of the cards, no one would be able to tell R9 280/280X/290/290X apart.
R9 280X tri-X looks identical to the R9 290/290X Tri-Xs, which means all 280/280X/290/290X cards can be re-badged into 370/370X/380/380X in a matter of weeks!!! Therefore, if you are re-branding, you don't need to change anything about the heatsinks, PCBs, literally nothing. You just need a new box, and a new sticker on the back of the PCB. AMD couldn't figure out how to do that for 6 months? Are we supposed to believe that?
So again, answer this: Why delay the launch of R9 370/370X/380/380X by a whopping 6 months if you can just take all the boxes for 200 series, throw them out, print new boxes and change the stickers on the back of the PCB? With cheap labour in China, this would cost peanuts to do.
Why would AMD push the launch of R9 300 series all the way to Q3 2015 if 90% of everything are pure rebrands? By rebrands I assume you mean 0 changes to the card's performance, perf/watt, etc., correct?
If they can't afford to improve to that level, they don't have any other options.
How can NV improve perf/watt by 60-70% with Maxwell but AMD can't even move it 10% in 1.5 years? You actually believe this? Also, going by what you are saying, R9 290 sells for $240-275 today and R9 290X for $280-350. So how in the world would rebranded R9 380/380X fit into this?
R9 270X =
$140
R9 280 =
$150
R9 280X =
$190
R9 290 =
$240
R9 290X =
$280
Not a single re-branding theorist on AT forums has been able to provide a clear answer of HOW exactly can AMD rebrand all of these cards?
Option 1: same or higher prices
If AMD can't gain market share at those prices i listed above, they can't just take those cards and raise prices. Keep prices the same also does nothing.
Option 2: lower prices
Consequently, if they are 100% rebranding and want to gain market share, they have to lower prices. Otherwise, the new cards
have to be faster, offer better features, superior perf/watt.
The re-branding theory
cannot reconcile how it's possible to re-release Pitcairn, Tahiti and Hawaii with identical performance and perf/watt at lower prices though because AMD is already losing $ with existing prices of the same cards!
Thus, the re-branding theory fails to explain how AMD can re-release identical cards at lower prices, the same prices or higher prices given AMD's GPU division's financial results in the last 2 quarters.