Hi,
Firstly, be sure it's a genuine enquiry from a reputable company. Beware if they ask you to pay for an appraisal.
As for the name, it seems ok to me. It's also a character in a certain Japanese media franchise, so might have some value in that area. I'd say low four figures, with any opening salvo towards the upper end of that. I see you've had a site on it for some years, so to a certain extent it depends on what you'd be happy to let your name go for.
Good luck