Good deal on 2 sets of inch/metric ball-end hex keys -- $11

If you don't have hex key without ball ends, you are missing out. The ball end allows you to tighten/loosen hex nuts from an angle up to 25%, which helps get around obstructions that would block a regular hex key set. Amazon has a good deal on a double set of ball-end hex keys (one metric, the other inch) for $11.