There are DIYs. And it's not overly complex, if you are good with tools.

If you are not, it's your house. You will end up saving about 10 grand, given your quote. But it is your house. You should consider the future value of the installation, as well as the value of a warranty.

Ignore the 'town inspector' worries. Mini splits are commonly installed by homeowners. You will need to use a licensed electrician, will need building permits, and potentially may need your main electric panel upgraded to a higher level of service.

Get the facts, do your homework. It can be done, but is it worth do it yourself in the long run.