Nah, 250 for me and similar for my wife, kids (x2) need 50 (if that) each I would think.
And a good portion of my "frivolities" would be stuff for the family anyway.
Holy crap, 1-2k per month on frivolities? I wish I was you Trousers.
I would say £250 per month would see me OK. TBH, I hardly every spend that each month anyway.