???? NPP AND prop together would be cheaper than Tren Acetate... I don't see why someone would do something like that on purpose unless he just charges so much it doesn't really matter to him?? I would think that it was an honest mistake, but it is still fu**ed up and he should make it up to you somehow... Maybe a free next cycle?
Anyway, I have made NPP like this with no problem:
150mg/ml NPP
2% BA
20% BB
Whatever oil you prefer.