Now you have me interested! What is the "resident's discount", how much is it, do you just have to show your retirement visa and passport?
Regarding medicines, last week at the best known private hospital in Pattaya, I was prescribed some tablets, went to the pharmacy and asked how much, she said 150 baht per tablet, but then whispered that is is cheaper outside.
Sure enough, another pharmacy gave me the exact same medicine for 100 baht each!