My (virtual) money is the R9 290 coming in around the $399 range and the R9 290X coming in around $499 for ref / std cards a bit more (+$50) for cards bundled with games or over clocked cards.

At those price points they'd be great bargain alternatives to the GTX 780's

Only reason I am leaning in that range is because currently not its really addressed by anything in the new lineup. Its also a "no brainer" value buy at those prices.