HHC 2011 was my first. Thinking back on it, I now wonder whether time and place could be made for swapping/buying/selling calculators and related stuff at the next HHC. I'd be an eager participant. Or has the idea been tried and failed, never to be resurrected?

In theory I see where that might work, I think it would be fun.

In practice, however, I think calculators make poor currency since they do not meet a critical part of Adam Smith's guidelines for a monetary system: they are indivisible.

It's also hard to agree on what constitutes a "reasonable" price.

At HHC2009 at least one presenter established a temporary booth and during break times sold some interesting items perhaps to fund the cost of the trip? Although I did not buy anything, I thought it was tastefully done and not out of place.

In HHC 2008 some attendees brought certain serial cables and other small manufactured items to sell, and in other years there has been one or two items of commercial interest, though I don't think it's ever been more than a handful of people exchanging anything.