[AitchEmArsey]

Agreed. Some UK numbers for reference:

£500/day is the absolute minimum for developer/DevOps outside London, £600/day much more common and including the cheap end for London. Senior is more often £800/day. You don't see values above that advertised, but people do obviously negotiate higher for specialist work; I have seen a mainframe developer charging £1500/day (on the low end of his range). Anything higher than that has always been a large consultancy rather than a freelancer. In my specialist niche I'd be asking for £1500/day top-end, expecting £800-1200 with negotiation depending on flexibility.