At any vendors that sell alcohol such as Project 12 and The Nightclub you can only purchase 1 beer during each shopping session. However any other drinks other than the beer (bottle) you can buy in multiples. I found this attempting to get the “Smart” Investor achievement. I then attempted the achievement using Tower Express and also failed and did not register my 200 purchases for the achievement.
Steps to Reproduce
Talk to Project 12/Nightclub vendor
Click to purchase beer multiple times
What I expected to happen
I can purchase more than one beer at a time.
What happened
I can only purchase one beer at a time.