BTW, I worked in prison and during basic training made Expert with pistols. Never shot a pistol or rifle before in my life. Course my targets were not people! I'm still proud of shooting like an expert though
I would say that a pellet gun is not going to stop any adult person. Child perhaps, urban animal possibly. A .22 LR pistol firing HP has the possibility of wounding or killing someone IF YOU ARE ACCURATE ENOUGH.
As for price, there are a lot of decent bullet chunkers out there under $500.