Was it a sin for me to lower myself in order to elevate you by preaching the gospel of God to you free of charge? (NIV)
But did I perhaps make a mistake and do you a wrong in debasing and cheapening myself so that you might be exalted and enriched in dignity and honor and happiness by preaching God's Gospel without expense to you? (AMP)
Have I committed an offence in abasing myself that ye might be exalted, because I have preached to you the gospel of God freely? (KJV)