Mountain Kat,
No, there are no convenience stores in Oak Beach. The closest place to get condoms, smokes or say rolling paper would be the Shell gas station on Montauk Hwy in West Islip. It is just east of the Robert Moses Causeway. It is about a 7 minute drive at 70 MPH from Oak Beach.
That CVS call really puzzles me because JB definitely knows that the CVS is open. He grew up right around the corner from there and it has always been a 24 hour CVS.
I think the key to this case is the 3-4 calls to the driver after 3AM. My guess is that MP got another gig for SG after JB's time. But she didn't want to go because she knows the guy and she is scared of him. I wonder if she knew of any of the other girls that went missing after receiving a high dollar offer from a "regular" and she knows her demise. The only problem is that MP already told the guy that he is in Oak Beach and he can deliver her to him shortly because he is close by. Once SG hears that MP told him they are in Oak Beach she freaks out! She knows she is in danger plus she is on a high from the stuff she smoked with JB.
I hope we get more info from LE soon!