I paraphrased it from this post
The auction said that Hollywood Heroes brokered the sale for a presenter. So, from that, I take it to mean a presenter that received this set wanted to sell but rather than post his/her own eBay auction they went to HH to sell it for them to give them some anonymity. Plus it's a high priced item so they may have wanted someone else to handle the receipt of payment and take care of shipping.
That's why it kind of surprised me that one of these sets came up for sale like that.
As I said, I can see the lure of the payout. $3k would have covered all my expenses for going to CIV plus put over $1k back in my pocket. Still, that's not the type of thing I would think to sell, it's so unique.