Nexus for me was $50/5 years, while Precheck alone was $80/5 years, so it was a no-brainer. Prices may have changed since then, though, because I believe I signed up in 2016.

The only difficult part was setting an afternoon aside to go get scanned/interviewed (if you even want to call it an interview, as I believe I was asked only one question: Why do you want this?).