Speaking of magic arms, clamps & grip gear, a while back I noticed some knock-off MIC "mini" magic arms with clamps, for $5.00 each, and free shipping. It seemed silly not to check it out, so I ordered one, and was VERY pleasantly surprised by what I received. While it's a LOT smaller (see images for sense of scale w/ standard-size clamp), the quality is surprisingly good. It's almost all metal, very strong, and when locked tight, it's TIGHT. Granted I wouldn't trust them to support a body and large lens, but they're ideal for mounting a speedlight, trigger, or similar item.
The clamps are only really large enough go around a lighting stand, but most of the time, that's enough. For $5.00 these seem an excellent bargain.