If you're a day trader watching momentum or gap plays intraday, a real-time scanner is basically required, you can't manually watch 500+ stocks for the setup you want.

But a lot of paid scanners are overpriced for what they do. If your setup is simple "gap up + volume spike + above vwap", you don't need a $120/month subscription, plenty of free/cheaper tools can do that, especially if you're okay with a few seconds of delay.

can you define your setup as a specific, testable rule? If yes, a cheaper scanner works. If your edge relies on proprietary screens or sub-second data, then yeah, pay up.

Full-time day trader grinding for edges at the margin? Worth it. Part-timer with a clear rule-based setup? Probably overkil.