scheduling agreement price maintenance authorization

Hi expert，

Now for SA maintenance in S4HC：

1. price must be maintained while SA creation;

2. if we remove condition type authorization in user role, user can't create SA.

Our client's demand:

Buyers are not allowed to maintain price in SA creation/change ,but they‘re responsible for creating/changing SA(exclude price).

Can we achieve this demand in S4HC？

Thanks in advance.