Right now Ace Hardware Outlet has the Master Magnetics 07293 Magnetic Floor Sweeper for only $13.69.
The Master Magnetics 07293 is a lightweight 14.5″ wide magnetic floor sweeper. Just a basic sweeper with no quick release or other bells and whistles, it should do the job clearing your driveway and shop of errant screws and nails. It would be hard to fabricate at that price. The next lowest price we found was on Amazon [What’s This?] at $17.22.
Master Magnetics 07293 Magnetic Floor Sweeper [acehardwareoutlet.com]