Can we use the phrase "for a change" to make a sarcastic comment or insulting comment like
Why don't we let her say this good news to others, for a change
Or
You have made quite a good point, for a change
Yes, it can be used sarcastically. It is fairly common. It implies that whatever you are suggesting is not common.
For example
He had a good idea, for a change.
That implies that his ideas are not normally good.
The examples in the question are perfectly fine "insulting comments," but they are not sarcasm.
The example in Gabriel's answer, while a correct usage, is also not sarcasm. If the person's ideas are not normally good, then it is just a straightforward statement (His ideas are not normally good, but for a change, this one is).
One way to use "for a change" sarcastically is to apply it to something that is in fact common.
Let's say John always eats Chinese food for lunch. One might say, "Hey, John, why don't I take you out for Chinese, for a change?" This is sarcasm, because it would, in fact, not be a change for John to have Chinese food.
