Pak’s sells all the convenience-store staples like milk, bread, radiator fluid, candy, smokes, 12-packs of Lone Star and what have you, but the quirky food mart near the border of Midtown and Montrose (a.k.a. the 527 Spur) also has a decent selection of $15-and-under nonrefrigerated wines and a $1.29 coffee-and-pastry…