Simply send them a stock email that tells them that you have had bad experiences with other recruiters and that to filter out the serious job offers from the shots in the dark, ask for 500$ before continuing any conversation.
Do not remove yourself from the market, simply price yourself too highly for them to bother. And asking for money up front sure shuts them up fast. You still maintain "good relations", stay polite, and, in the worst case, you get 500$ to send them your C.V.