Britax B-Safe 30 base station

Long story short, we bought this from Babies R Us before moving here (arrived in May and baby born that month). It arrived in our household goods 3 weeks ago and now I found out today that it's the wrong model for our car seat. I paid $80 + tax but am asking $50. It's brand new, never used, just out of the box (which had been thrown away before we realized it was the wrong model). Smoke free, pet free home.