You only pay when you make a hire.
If a hire is made from a “Legacy agency” submission the fee is set by you. There is no markup and no economic impact to you at all. 1% is deducted from the agency's fee.
If a hire is made from a “Community agency” submission the fee is 14% of first year salary in North America. Community fees vary around the world. See HERE for details.
There are no other fees of any kind. Ever.