For the record I do not endorse bowing to the pressure of the gsuite/office365 monopolists.
One of the important parts that's hard to solve for a person who doesn't work at an ISP these days is that you absolutely don't want to be in a /24 netblock (and parent /22, /20, etc) that also contains $5 per month VPS/VM/hosting customers.
Because the inevitable result of having shared hosting IP space where anyone with a pulse and credit card can buy a VM for one month for 5 dollars is that your IP space will end up on some blacklists/spam lists/opaque and not publicly available spam-blockage lists run by gmail, because other peoples' server IPs in the same adjacent ranges announced into global BGP tables by the same ASN have historically been a source of spam/UCE within the past 12, 24, 36 months.