At least you didn't double down on the basic error, oh wait hold on...
"... silly £6000 per month!!!" . Certainly provided a good chuckle
So I estimated £1500 a week and you estimated a tad more at £1657.33 a week. Tbh I hope he's on a little less, I suggested the top of my range to emphasise that be it £5000-6000 pm it is nothing when signing a long term deal.