I just bought tretinoin (generic Retin-A) after not filling the RX for years, b/c I found a coupon to cover a significant part of the rx online. My insurance wouldn't pay for it at all b/c they consider it cosmetic, and my doc wasn't going to argue that it wasn't. Anyway, with the coupon, I was able to get it for less than $60, instead of hundreds.
https://m.goodrx.com/tretinoin
I've been ignoring the annoying "goodrx" commercials on tv, b'c I'm not a fan of drug companies keeping prices artificially high and discounting through coupons. However, I do have chronic medical issues, and I've now used the site a coupon times and been able to purchase medicine I probably otherwise would have ruled out due to expense. Unfortunately, the site is worth checking out. Make sure you input the correct dosage before you complete the info. -- Tip to save paper, I never print out the cards I just take a photo of them with my cell phone and then show it to the pharmacist.