Can someone translate "ขอบอกว่า"? Thanks.

It means "let me say..." or "allow me to tell you..."

Thanks Rikker. I used to hear this often on the news. Would you happen to have an example of how one uses this? A full sentence, maybe?

คนนั้นชอบอวดเก่งตลอด แต่ขอบอกว่าเขาไม่เก่งเลย

That person likes to brag all the time, but let me tell you, he's not good at anything.

Something like that.