Well, it wasn't just Google. Microsoft cut out the free custom email domain for OneDrive, Zoho cut theirs way down -- so my feeling is that it had to have been abused in some way, even if it wasn't strictly spam.
$6 monthly with unlimited (or some high number) of family member users would be fine.
Any cost at all will limit spammers.
I’m happy to pay. I’m not willing to pay $25 - $30 a month for basic email just because I want separate inboxes and a custom domain.