No, it's a ammo packs price hehe
Try setting zp_disable_money to 0
Bug found - when one respawns / gets disinfected w/ cvars: zp_buy_custom_grenades and zp_give_all_grenades both set to 1 and rebuy option on, one can produce this graphic glitch: (IMO extra Item/WeapPickup message, didn't looked into a code)
Although it doesn't give user extra nades and is only a graphical, is a bug.
EDIT: Added an image as attachment.
+ one more bug (maybe) - nemesis can't kill you if you have some armor, just like normal zombie.
EDIT2: Also, it can infect in "normal" modes (standard and multi-infection) - don't know if it's intended or not.