The only price to this feature is some disk usage.
If you want to disable System Restore, which is a bad idea, it’s really pretty simple.
Just to verify you understand: Software has bugs.
Disabling System Restore will keep you from rolling back changes.
It is not a good idea to disable it.
(Note again that this is probably a bad idea).
That should be all you should probably do.
Now you’ve got system restore disabled.
Living on the edge, eh?