A drug dealer
arterian
Property dealer, Estate Agent
A person who sells newspapers and journals is typically called a newspaper vendor or a newsagent.
...is illegal I can only do so much with incomplete sentences.
An art dealer is a person who buys and sells paintings and/or sculptures.
A gunsmith or an arms dealer. A weapons manufacturer if they make the guns that they sell. Your Friend, Sleek Mouse
A Pharmacist A drug dealer
who is a mercer
It's a dealer
Pharmacist.
That would be an Entomologist. The study of insects, entomology.