Ok, let's think about this.
You want to do this, why? Because you think that someone will say "yea, that's worth it, here's my $50" or you think that people will start thinking discretion is the better part of valour?
If it's the latter, then you don't want people to cough up doe. You want the ability to do that gone.
I'm not saying it's a bad idea, I'm saying cut to the chase.