Just to point out that AMD competition has very little to do with prices. Apple has competition but still have rocket high prices, in fact Apple frequently have worse phones than Samsung in terms of performance, yet charge way more. It's because customers pay more when asked, nothing else.
If Nvidia guys give a flat no to £620 for this card.... Nvidia will drop the price to sell them completely independently of what AMD can provide. The consumer has a huge amount of the power to control if they overpay for a product or not. There is a tipping point, IE Nvidia might need to make $250 to cover costs at all and might want $400 to make a healthy profit to cover all R&D costs. Which means if they price it at $600 and no one buys they'll drop the price towards fair, but once it hits $400 it depends on what sales are. If they think they can double sales by dropping a further $50 it makes sense, if they think they will only increase sales by 20% more by dropping to $350(which would be a 33% drop in profit) then it makes no sense.
The consumer doesn't have absolute control of the cards price but they absolutely have control to put the prices down into the reasonable range of sensible profit for Nvidia simply by exercising some self control.
The problem is when people don't, it just lets Nvidia know their customers have no sense and will pay more so they'll charge more again for the next card and they'll keep raising prices until even Easyrider is like "wait, this actually doesn't make sense anymore". Companies will keep raising prices exactly up to the point the consumer doesn't let them... the consumer choses exactly where that point is, not Nvidia.