Security is important, but I’d also check how much power your PC uses when idle… Depending on the type of PC (desktop, laptop, …) and its hardware parts, it may draw quite a lot of power if it were to stay ON 24/7.
Nodes do not get SNOs a high revenue, especially during the first year. You may find this community estimator handy: copy it to your Google account and fill in your numbers to have an idea on what it could get you and if it would cover your electricity costs of running your PC 24/7: