You can do what I do. Tell him to go ahead and have his buddy send you the check. I have a pile of fake checks and money orders. They all look fairly realistic. Some look perfect.
If you want to have extra fun tell him you have a local guy buying the machine, but that you don't think the local guy is qualified to fly it. If he can overnight the check to you, then you have a reasonable excuse to sell it to the first buyer (him). And you cost him $20 for overnighting a fake check.
Oh yeah, after he sends the fake check you need to continue the fun by responding to all his emails with messed up unresponsive emails. Tell him you've already shipped it. In the next email tell him you're going to ship it soon. Then tell him some shipper came by and picked it up. Then tell him you can't ship until the check clears. Then maybe say "check - what check?" Have fun, be creative.