Comparison: Mangools KWFinder vs Ahrefs for low-competition keyword research

Hi everyone! I'm just starting to really dig into keyword research for my work.

I've seen a lot of people recommend Ahrefs, but it seems pretty advanced and expensive for where I'm at. I'm mostly looking for low-competition, long-tail keywords to start with.

I keep hearing about Mangools KWFinder being good for beginners and specifically for finding "low-hanging fruit." Is that true? For someone just doing research for a few small B2B SaaS projects, is KWFinder's data good enough, or will I quickly outgrow it and need Ahrefs anyway?

Mainly curious about the accuracy of their keyword difficulty scores and the actual database size for those more niche terms. Thanks!