Triplex with a "kicker"

[Curtis Denny]

I'm working a deal on a triplex ( all 1 bdrm and occupied) where the math works. Here's the kicker... It comes with an extra lot directly across the street (deeded as one lot) the seller looks like he has priced the extra "lot" into the price. My question is should I try to negotiate the lot price out ( which he seems unwilling) or maybe.... Build another set with 2 bdrms.