In my quest for a simple setting on the PSN store that would alert me as to discounts to items on my wishlist (such as the wonderful system on Steam does), I have found that no such setting exists, but there does exist a website that does it for you, provided you register your email and add your desired games manually:
https://psprices.com/region-us/index
You can change the store region, and despite its PSPrices name, it also works for Xbox/Nintendo systems.
I hope somebody finds this useful.
Last edited by Xen - on 29 January 2018