Are there any downsides to declining Phi Beta Kappa?

I was invited to join PBK for the second time at my university recently, but since I'd have to pay money I'm probably not going to sign up. Are there any things I might miss out on from declining PBK? I've already read how little it matters to adcoms, so I'm even less inclined to consider it at this point.
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Tags: Pre-Medical - MD Source Type: forums