If he charges for the tickets he'll get only devotees, but if they have been used to free rallies will they want to pay now?
Of course they will! Because it won't be 'paying for a ticket to attend'. It'll be a 'donation for a chance to meet'. I've seen similar for candidates of both parties. Usually very pricy dinners with a chance to meet . The campaign racks up the $$$$ and one sap gets a handshake and a photo op. Except in this case it'll be a shell game and no one will ever know that no one 'real' got to meet Scrotus. It'll be some pre-selected 'plant'. But in this case I think they'd only be able to get away with charging a 'token' fee. Maybe $10.00 - 15.00pp? But who knows, his supporters may feel that, oh, $50.00 isn't too much to 'show the love'. I'm sure most of them have donated at least that much to his campaign, even if it's been in dribs and drabs.
Or they'll just say "So sorry but we HAVE to start charging now because of the DEMS! It's all their fault!!!".
My question would be more along the lines of "Will someone be willing to pay for a ticket to block a REAL supporter from attending?".