I don't think that's likely.
A home miner I know just bought 16 vanilla Vega 64s at the SRP +£100 price (£549). He feels he got a bargain.
Hashing performance (per watt) might not be great as of now, but a lot of miners are betting on software optimisation, possible BIOS mods and the new mining ISA.
Outside of OCUK and perhaps a few others being charitable to gamers, like they have been with 570s and 580s with lower than demand dictated prices, finding SRP (£450) is likely a pipe dream for the foreseeable future. Unless the new mining ISA is quickly proved to be a bust (doubtful), then these will probably go for £650 or more soon.