Another meaning for being 'tight', penny-pinching or a scrooge with your money. Whatever is necessary, a 'Rehro' would pull out all the stops (or not flush the toilet) to save a few pennies.
Originating from a popular late 90s t.v. advertisement from Ferraro Rocher. Hence, 'FerRARO' becoming 'rehro'.
Mark: Stephen, it's too cold in your house. Can you ask Patricia to turn the heating on?
Stephen: What?! Good one!! That would cost money. It's only mid-January.
Mark: Stop being so fuckin' 'REHRO'!