Every day of the year I'd do a 1:1 trade. If you're making money from it that's just bonus. $130 from $249 44% off for an open box. If it is in good condition this feels like a no brainer.
I know some people disagree, but I've always really liked AMOLED screens. Those deep blacks are gorgeous. You're also going to lose your removable battery and expandable storage, and a tenth of an inch of screen space.
All that said, I own a Nexus 4 and love it. As long as you know what you're getting into, I say go for it.