I bought a chepo one on ebay for $14 that was magnetic just to try it out before buying a good one. You might consider that route, see if it is for you and then buy something nice.
I love having it, just to keep the spare junk like glasses, ear buds, a few bungy cords, garage door opener that sort of thing. Ill probably upgrade to one that mounts on the gas tank ring. That seems to be the best solution I have looked at.