Slightly worse for slightly cheaper could still be attractive. Factor in prices for displays with freesync display vs displays with gsync, and the price difference to Nvidia get a a lot bigger, in favor of AMD. But it depends on whether the cards will be available, and which performance will be reached.
Seeing as the Vega 64 "starts at" $500 and I was able to pick up a 1080 TI for about $700 I don't see who the target audience is. If you are the part of the market that is willing to spend $500+ just for a new graphics card then you likely aren't going to get the subpar card just to save a few dollars.
If you already have a G-Sync display, you're kind of locked in. I had super high hopes for Vega (if only to apply downwards pressure to NVIDIA's pricing), but ended upgrading from a 980 to a 1080TI a couple of months ago as the launch was dragging out.
With the numbers I'm seeing, I'm glad I chose the TI, and didn't wait. I don't see NVIDIA reducing their pricing over this.
