I'd pay £60m if I had to. Walker is the best in England comfortably and as people are very quick to point out, we don't have a single right back, ergo we don't have a single piece of leverage with the deal.
Would we rather Walker didn't sign but the moral high ground of '£50m is too much' being upheld make anyone feel better because it sure as hell wouldn't me?
The money is high but look at the market! Swansea rejected £40m for Sigurdsson, Everton paid £30m for a Championship keeper and Chelsea are about to pay £40m for a player who will miss preseason and won't be available until September as he had the fluid removed from his knees.
Get him in, get him integrated and fix one of two glaring problems with our squad with a great player.