$310 for a Progressive Industries EMS-PT30C, or $258 for the EMC-LCHW30C hardwired in, and all these worries will be history. Your A/C will run, or if there is an undervoltage, the EMS will shut things down to protect the compressor from burning out due to low voltage.
Caveat: Make sure the electrician is installing a 30A, 120VAC connection. I've read about way too many fricasseed RVs when they end up with a "dryer outlet" that has two 120VAC hots and a neutral as opposed to a hot, a neutral, and a ground.
In fact, if you are getting an electrician to install a pedestal, might as well go for a 50 ampere pedestal with a 50 amp, 30 amp, and a 20 amp series of receptacles. In the scheme of things, this won't be that much more on top of the exiting electrician costs, but you will gain a lot more functionality.