Trump's PAC is paying his legal fees, not Trump himself. So far the Save America PAC seems to have spent at least 10 million on legal fees for the former president.
Not only that, but he lies to his lawyers and refuses to listen to him. Combine those and most lawyers wouldn't touch him with a twenty foot pole.
He's left with bottom of the barrel barely-lawyers who are looking to make a name for themselves and True Believer lawyers who are willing to crime all the crimes alongside Trump because MAGA. Neither of these provide good legal representation.