Update: I went to a walk-in clinic and got a prescription for 30 generic (25mg) Viagra pills. I went to a Costco pharmacy this time. They only had 12 which was $107.64 and told me to come back for the rest the following day. When I went to pick up the balance of 18 pills, I thought I'd have to pay another $161.46, but to my surprise, there was no charge. That means the pills work out to just $3.59 ea. or $107.64 for 30 pills. I can't remember how much I paid for the same quantity at Shoppers last time, but it was over $300.