They are 130 bucks each, for a pair it'd run you $260 for the subs... I haven't a clue where you're coming up with $310, but these are the exact same thing mechanically, as any other BNIB one. minor cosmetic defects may be apparent.
That's an example of my b-stock sub. If not having that is worth $50 more each, plus tax, plus shipping... which would probably come out to being closer to $200 more, then by all means, wait till you have the cash. But otherwise, you're not gonna find a better subwoofer for what you're looking for, at anywhere near a better deal.
Not trying to force you into anything, But it's a sub that you'll absolutely love, at a price that you'll regret passing up.