Not every new member need to pay some bitcoin when registering, only if he register using evil ip which usually if he/she using vpn or tor.
Some newbies in the local forum complained that they were banned after registration due to the "Evil IP", but they didn't use neither VPN nor TOR. And it seems that the blocking happens pretty often. I guess that the new user must have a static IP-address to register a normal account here.
In my opinion, increasing the payment of new registered account won't diminish the garbage posting. As a decision that was suggested by other user, Jr. Members must be forced to get merits and become a Member to join an ICO signature campaign.