Some of these responses are ridiculous. Bring a gun? That's a good way to get yourself arrested, or worse yet shot. Getting pulled over with a gun and dope, you're immediately classified differently by the police. There's no longer any insinuation of "recovery", in their eyes you've become a menace to society that needs to be locked up once you ride around with a gun. Even legally purchased, I'm pretty sure there might be bylaws that make it illegal to purchase drugs, be in a so-called "high drug activity zone", or have drugs with you, let alone dope, in the car even with a CCP. You will then become LEO's golden goose, if you thought $200 grams were a rip-off, think about facing jail time or a 10K fine + losing your job/benefits in exchange for the piglets' "protection".
You are this guy's golden goose. The one that ran upto your car to give you his new number is exactly that, just a new number looking to make you his golden goose. Of course he wants to fuck you. Since when are dope dealers some type of elite businessmen focused 100% on their money? Even then, those type of people pay girls to fuck them or hang out with them. Its just the shitty nature of society.
Don't think for a second these guy's end-game is anything less than milking every last dollar out of you. Project apartments? They cannot due to one issue or another, pay their rent, thats why they're selling dope. If that guy was gonna rob you, don't you think he'd just run upto you right there and then with a gun and take your phone, car, everything? It's not like there's some master plot of checks and balances before they "decide" its time to rob you. They will just roll through and rob you if that happens, there is no predicting it. Hell, even people I have had prior issues with who I more or less knew robbed people on the regular, I still hit them up when others were dry and they still sold me (albeit, shit-tacular) dope. I was relatively broke at the time with no car and scrounging up $40 just to get well but still. I wouldn't read too much into things, check out the new number maybe he will come through or maybe he will be even less reliable than the guy you're picking up through right now (who, TBH, sounds more like he's the type of guy to middle man enough for his fix over and over, and yes that type of guy can start robbing if for one reason or another things dry up).