You've got it completely backwards and obviously spend way too much time on boards like this thinking they represent the average PC gamer.
Look at the valve survey for the average gamer. Its a 60hz monitor and 4gb main memory [actually its 8gb thankfully but
GFX 1gb is the most common]. I believe 4 core cpu is now mainstream however, a good move forward and hopefully ryzen pushes us to 6 core by the next gen of cards
This Vega release doesnt even apply to average, 480 is already there. Price range would be around 200 which is low as every year the worth of £200 is growing less and less however tech is advancing its unfortunate if peoples budgets are perhaps getting smaller.
Even the lower vega card wont come close to average, it'll be 1070 level? If thats the case I got to agree the higher Vega card is going to be in competition with the 1080 both price and performance. The pricing of 1080ti is near the top end of the scale in what can be justified for performance, there is a kinda drop off where numbers of customers just dont justify the R&D and scales of economy mean certain failure. So I dont see AMD pushing in that direction if its not even profitable for them especially.
Vega does require that shock and awe effect where people reevaluate if they are on the right train. We already seen from this thread, a lot of high performance users feel they are locked to nvidia by their monitor choice. So AMD is going to need a card so new and amazing it can jump that Nvidia train and its passengers off its rails onto their business path with impressive features and advances.
I can see why they target VR when its so hard to win a race already in motion and also I hope AMD is pushing Vulkan forward and we see more of open standards allowing for innovation by either team not all this bias in games to one card or the other