They could certainly save money by doing it differently.
Why not ban all political party involvement and only allow people to stand in their own names as independents, with strict limits on the money they spend and where it comes from. They could profess broad support for a party but not be supported, or restricted, by it. Independents already play significant roles in local government, being people who genuinely care about their locality rather than their political future. This would enhance that. They would need to convince people directly, on the doorstep, in public meetings and on TV. Rather than just because of a label. As our national politicians often cut their teeth in local politics this would produce people we want, rather than those we are given.