I wouldn't say it was worth very much at all, unless you're making it as an emotionally driven purchase, but I'm not really a fan of .me as an extension apart from the odd verb hack, date.me, love.me etc and even then I don't rate them value wise.
If you really want it then I'd probably not go any higher than £100, but that's only if you want it and you've got a good reason for using it. Beware that 99.99% of the public have no idea what .me actually is, so many are likely to try to visit KernowMe.com or KernowMe.co.uk etc etc if you show them the URL and ask them to visit it later.
If you're just looking for a brandable type extension, want the Kernow by itself and you're in a tight budget, why not just register Kernow.in at Dynadot for $3.75 (about £2 odd)?
Ty