Don't forget that $100 ball doesn't have any holes in it. You might get a TNV or NMB for $140 but you still gotta get it drilled. You might save some money, it depends strongly on the area you live in. Make sure you budget for drilling. If you only have about $140 to spend to get her on the lanes with this ball, then a NMB isn't going to work.
Further, the Total NV is not exactly a heavy oil ball. Pearl balls with mirror finishes tend to, you know, skid, and that's not the usual "heavy oil" reaction most people look for. The Beat'n is more of a heavy oil ball.
Make sure that a heavy oil ball is really what your girlfriend needs. I'd stay away from oddball, strong asymmetric cores like the Beat'n's, too. The Anger is supposed to be a good ball for the price, and it's got a simple symmetric core.
SH