I didn't have the 75 bucks for a fret leveling beam. Ron Kirn, posting on tdpri.com, suggests a piece of scrap counter top. They are amazingly flat. I got a 3.25" x 29.9" chunk of quartz polymer free at a local counter place. Corian and granite also work, but Corian seems a bit light, and natural stones are fragile. I found affordable rolls of self-adhesive 220 and 320 grit sandpaper on eBay.