Wait, you're trying to get the Steam account? The title sounds like you're selling one...
I have a Steam account with whole BF series, CoD:WW (sucks with Steam), CoD:MW2, more or less everything that is based on the Source engine, everything that has Half Life in it's name as well as SC & SC2. Maybe a bit of an overkill if you want just BF:BC2. + I'm still playing BC2, and CS occasionally, so you're not getting it for free.
If anyone has an acc with just BF:BC2 I might be interested in trading (with a bit of moneh for the extra games ^^)