Custodians making 30 grand a year and my dad's acting like he found a gold mine. Too good to be true?

I'm not a custodian, but I have heard of some custodians making up to 52k per year. It is possible, it just depends on the company. One of my good friend's mother makes 49k a year and she a custodian for a high school. Of course she's been with for almost 20 years now so that salary could be a little misleading for someone new to the industry.