Maybe its just me, but for a couple bucks a pair, with one pair required per handle and one pair per set of lines, the insurance of using commercially available hardware well outweighs the cost savings. Not to mention the PITA factor of dealing with bending music wire and hoping it doesn't fail, at best reducing the plane to toothpicks and at worst creating a fly-away condition.
Some people involved with the hobby can probably fabricate a substitute easily and safely, while others will be putting themselves and anyone around them in danger trying to save a few dollars.