My finances are in similarly poor shape for the last 2 years now (why it’s so is a long story), so I know exactly how you feel. For what it’s worth, a surge protector is much cheaper, but only helps with overvoltage, not undervoltage AFAIK. Still could potentially save your PC, not from a failed bios flash, but from any weird surges. But if you have a high quality PSU, it can probably handle somewhat unstable power. I just googled mine and it says it has full-range active PFC, automatically handling the input voltage range of 100V to 240V - though the grid here is 230V per phase so I should probably get a surge protector myself. Those are like 20€ new apparently. If you’re on a lower voltage grid like in the US and your PSU has a similar range, you probably don’t need to worry about overvoltage.
My finances are in similarly poor shape for the last 2 years now (why it’s so is a long story), so I know exactly how you feel. For what it’s worth, a surge protector is much cheaper, but only helps with overvoltage, not undervoltage AFAIK. Still could potentially save your PC, not from a failed bios flash, but from any weird surges. But if you have a high quality PSU, it can probably handle somewhat unstable power. I just googled mine and it says it has full-range active PFC, automatically handling the input voltage range of 100V to 240V - though the grid here is 230V per phase so I should probably get a surge protector myself. Those are like 20€ new apparently. If you’re on a lower voltage grid like in the US and your PSU has a similar range, you probably don’t need to worry about overvoltage.