Oh, hey, thanks! I looked and looked, and I could not find a 6mm under $60. The one you linked is inexpensive enough. To the rest of your comment, I am unlikely to break the broach, especially in aluminum, but had I borrowed one and broken it, of course I would pay for it. Making the bushing is not a huge deal, of course. I just have to buy the metal. 'Steel, probably.
Edit: Oh, wait. It's $10 shipping, pushing the price to a bit over $24, which is still a bit pricey for a tool I am unlikely ever to use again. What's worse, it may take up to 2 months to get here. That's not good.