V8vega
He messed up, yes.
Are you really out $100?
4 vibration mounts are $15-$20 shipped if you get generic ones out of an industrial catalog like McMaster-Carr.
3 RPM chips 7000,8000,9000 you probably won't use anyway. $5 for the one you might use.
They don't come with retard chips, do they? $5 a chip if they do.
If the MSD box works, your not out that much.
He still should have told you those items were missing, so you would have had a choice to buy or not without them.