Oh my. Behind a single /24 subnet, that’s totally impossible. Have a look at @BrightSilence’s estimator to have a rough idea on what to expect, and how long it takes to “ramp up” the return on investment (copy the google sheet in your account, then fill in your numbers):
In 10 years, you would still earn less than 150$ per month (by providing 40TB of storage), if network activity were to stay roughly the same as it is these days.
Everyone’s hopping for the network and its usage to scale up. But even if it did, more SNOs would probably join in, which means that it wouldn’t necessarily increase that much what a single SNO can earn.
If you have several IPs behind different /24 subnets, then it’s different as you could store more and faster, making your earning go up quicker.
But unless you have a lot of different IPs, being an SNO is not the best recipe for getting rich.
Not yet anyway…