It doesn’t cost that much...that’s ridiculous. I installed a 240v Tesla charger and the cost was maybe $400 for materials, total. Granted, I did the work myself, but in no way should it cost $6500.
But it'll be like anything else, you'll get the service and the components you pay for...some will be scammers, so beware.
The real worry is "Sure, by brother-in-law can put that in for ya, no problem." Then something overheats or shorts out and your house burns...maybe with you in it.