I want to start the quest on contreras's side so i can get this machine and him as a vendor, but when i try to talk to him he wont give me any more dialogue options than selling his wares. Are there any fixes? im level 16 if that matters

YOU PROBABLY KILLED SOMEONE RELATED TO THAT QUEST, LIKE THAT GUN RUNNER GUY

You can still get This Machine by turning him in to Lt. Boyd.

You probably need more NCR fame. I remember he wouldn't really deal with me when i went there at level 1.

It might be a glitch to, first time I tried to do that quest I had to re-load a earlier save because I had the same problem your having. Second time I convinced the undercover ranger at westside to keep quiet but Contreras still said I needed to deal with him, so I had to go back and shoot him just so I could get this machine.

TBH you should just turn the [censored] in. His inventory isn't anything special anyways, and it takes 2 years to walk to him from the fast travel spot.

Walk all that way for him and he won't help you. Damn