Buying a girl would either mean:
A) She's doing just for the money, which would be prostitution (not bad in itself, just bad for a girlfriend)
B) She'd be forced against her will, in which case she'd be some god awful uneducated stupid east european/african/whatever poor oppressed place who'd be more trouble than fun.
If I could buy an intelligent and refined young girl with some self-confidence then yeah.
Pic related, although overdoing it.