When I lived in Sydney I had a few friends that frequently bought Rikodeine (dihydrocodeine cough syrup), which is also meant to be tracked via pharmacists recording IDs. My friends knew what pharmacies didn't bother to track it, normally if you were a 'repeat' customer and knew the pharmacist. They were able to buy 10~ bottles in a day from 8 - 10 pharmacies, repeating every few days. This was also in Sydney's central cbd so there's a pharmacy every other block.

I assume the situation is similar with pseudoephedrine, though the drug class/restrictions may be different.