It's simple, the 5870 was priced at $379 at launch, the 6970 was $369, the 4870 were around $289 and the 7970 is $549.
The cheapest equivalent card at that price point will be the 7890, the lowest card of the Tahiti series (Tahiti LE).
We will have 3 more cards occupying the enthusiast market that was not present during the 5800 series launch, that is 7950 3GB, 7950 1.5GB and 7990 6GB, all being more expensive than the last three launches of the top AMD range (considering single core cards only).
This is clearly a new marketing strategy from AMD, it can go either way from now. People might be put off by the new pricing strategy and the mainstream cards might now warrant enough improvement for the cost of the upgrade, OR they will simply hold out until Nvidia comes out with their new offerings (which may be weeks or months from now, we don't know). In that case we can of course expect some major price drops in the future. The alternative is that people will buy into this scheme, prices don't drop, Nvidia releases their new cards and having an established customer base, they simply adjust their prices accordingly, entire AMD range goes down by say 10% but nothing more than that, people will upgrade anyway for whatever reason or start justifying increased spending, etc.
I mean, are these cards really a game changer? Radeon 6950s in Crossfire are still beating these and any other single cards on the market, offering the most value for money. Even though this is pretty close now, one would say going with a single card is the wisest option (especially if you choose to buy for £420 and not spend £100 extra to think that it makes you any cooler), but shouldn't we expect some value for money too? For all we know, nothing has changed, we just get a replacement for the Crossfire configs for the same money but value for money it is not. And certainly the lower range won't change that unless AMD plans a huge price gaps in their entire range.
Me, I'm holding out for Kepler. Sure, they might not be the best cards to get when they're out but they need to change something on the market, whether it's price drops on AMD's cards, more performance or just better value and that's what I'm hoping for.
Here's hoping for some dirt cheap 6950s on the MM to keep me going in the meantime.