When I worked at Walgreens, they just limited the amount you could purchase of those kind of drugs in one purchase. If you brought a bunch to the coiunter the computerized register wouldn't let you ring it up. Large amounts of this drug are used to make meth, which I'm sure everyone knows.
If you weren't trying to buy a bunch, I would definitely inquire. Maybe they've changed the rules and go by telephone numbers or something. If you really need sudafed, which is a wonderful decongestant, I'd suggest going to CVS or Walmart or even your local grocery store. You should be fine if you only need it for the occasional cold and are buying consumer-sized portions. Try some vitamin C too. That's stuff's still legal!