Unpopular opinion: I started using a cheap magnetic level from Harbor Freight on my rail alignments.
Figured it would be fine for a quick check, but it was off by a full 1/16 over 10 feet compared to my Starrett. Now I'm wondering if anyone has actually found a decent budget level for spot checks, or if it's just a waste of money.
Come on, a 1/16 over ten feet is nothing for most jobs! That Harbor Freight level is perfect for the price. For quick spot checks and rough framing, it gets you 95% of the way there. Not every project needs Starrett precision, and that little magnet is so handy. Sometimes good enough is actually good enough.
Yeah that "good enough is actually good enough" line from @jackson.wesley is spot on for rough work. Read a forum post where a guy checked his HF level against a machinist square and it was dead on. For hanging a door or slapping up a wall, that 1/16 drift over ten feet just doesn't matter. The magnet saves so much time when you're working alone.