Today you cant make changes to all your members in a batch or at once. You need to make changes to each and every one. When you have around 500 members this takes weeks and there is a lot of mistakes done. We tried this once to change the taxes. Took forever.
Now we are planing to race the price for all our members. Just got the word from your team that I need to change this on every one again :(
What you should have is either a batch updating or linked memberships. So there is a way to update settings for all. With batch you can make it so you can choose what to overwrite or not. Like the base price but then not change discounts or payment dates etc.
Today you cant really make changes to a bigger group and that is a big must sadly.