I realize that, just saying, in your calcs you list the difference as 3.8 or something. Thats all things being equal. I was just pointing out that the ML cost difference was not accounted for.
Actually checked in game. have a +1 shock shortsword of smiting. its ML 12
+4 acid q-staff of GCB is ML 14.
+1 greater bane is lev 6/ +1 smiter is 10. Lev dif is 4. So the greater bane can get one of these six things that the smiter cannot:
1)+2 hit/dam
2) 1d6 and +1 hit/dam
3) 2d6
4) 1d6 + burst
5) 2d6 +burst -1 hit and dam
6) burst +1 hit and dam
The most a smiter could theoretically get back as far as costs go is when comparing a +5 2d6 w/ burst greater bane (ML 20 item, most cost avail to a greater bane) with a +4 2d6 w/ burst smiter with a racial req (ML 20)