I'm not going to check your calculations if you've made any mistakes but that does seem about right. Firstly I'd like to point out to you that things such as suit, wings, eye, hair, faces are just extras. If you are trying to say through your post that it is too expensive to perm items there's always other methods which can be used.
Method 1: Make your outfit, hat and glasses perm. That way you can easily upkeep your accesorys and maybe added extras with vouchers without having to spend lots of money.
Method 2: Do not purchase extras such as hair, face, eyes and glasses. This way you can easily upkeep the rest of your items with vouchers, without having to spend any real money
There are many methods that can be used to be efficient, you don't have to spend a load of money to be able to upkeep your items.