Plenty of Eileen's out there, although it's not as popular as a baby name any more which will reduce your target market. Also, first names tend to be more vanity domains than surnames - people like firstname@surname as their email address because it works for the whole family. I'd personally list it with a guide price of £1000 and consider offers above around £250, but I'm still pretty new at the game so I might be undervaluing it. Hannah has just broken the £500 barrier but is a far more popular current name - I'd guess Eileen is worth about half what Hannah ends up fetching.