Thoughts on the 'need' factor of a main line surge protector

Its on my wish list, in the mean time, I have a monitor (displays voltage and checks for miswired) that I use to check before plugging in. I then plug it into the outlet near the sink so I can easily see it so if voltage drops too low I can turn off AC. It is not automatic, but it is what I have until I can budget the EMS.