PT24.S3.Q23

I don't understand how B is correct. It states that "a piece of narrow floorboard was NOT SIGNIFICANTLY LESS EXPENSIVE than a piece of wide floorboard'." However, how does that translate to narrow boards being more expensive--which I believe would make narrow boards a status symbol. Going by the phrasing- they could be only a little less expensive, or simply the same price. Please help and earn my eternal lsat blessings :)

Admin Note: https://classic.7sage.com/lsat_explanations/lsat-24-section-3-question-23/