did you list have Cactopus cream, Herbal Scrambled Eggs and Medicinal Soap? If it did then your buy times must suck. These things( minues the Cream) stock in large bulk amounts, you should be able to snag at least 3 of each per hour/3 restocks.
I know this for a fact because I used to legit restock at Pharm and would be able to, at times, get as much as three eggs per restock.
If you ran it for 6 hours and only got 4k then increase your refresh speed and buy times, this shouldn't happen.
Had all of those and more.
Refresh rate of 4 to 10.
Delay is 1.5 - 2 and 1.5 - 2