for something that will project a level line over 50' and in all
directions...you're gonna have to spend a few hundred bucks for something
with the accuracy you need ..even if the B&D units were accurate at 10' at
50' they probably wouldn't be in the ballpark. Your percentage of error
factor increases pretty quickly at you reach out to or past the limits of
the laser light. The box store/walmart levels are good for hanging a
picture on the wall 3' away (regardless of their ads)
unless you're getting into foundation or grade work or hanging ceilings for
a living, it's hard to justify the expense.
I agree with the previous post... rent it for a day for 50 bucks and be
done with it. It's too expensive a toy to just sit in the box on a shelf.
TIME ... it's what keeps everything from happening all at once !