Whenever wine, liquor, or beer companies change their label colors or bottle shapes, distributors know who wants their suddenly outmoded merchandise: Suhail Saba, the owner of the Parkview Market. "I buy it all, I buy everything," he says with a laugh. "I have a huge basement." And bargain basement prices. If you don't mind buying "same liquor, different bottle," as Saba puts it, you can get Sauza Hacienda tequila for $13.99 (retail: $27.99); Bushmills or Bulleit for $19.99; and any number of $20 bottles of wine for a quarter of that. Saba's $5.99 six-packs of Guinness Extra Stout may be the cheapest in the western hemisphere. Those with less discriminating tastes can walk out the door with a 16-ounce Budweiser for a dollar. Customers from as far off as Potrero, North Beach, and even Pacifica do just that.