While I disagree with
your other proposal, I do agree that this one should be implemented. Currently the Auctions sections is a mess due to the variety of the things people sell, so separate sub-forums could work well.
Perhaps it could be similar to the Goods section in where there is a 'Digital Goods' and 'Collectibles' section, since those are the most popular things to be auctioned. Any miscellaneous auctions or questions could then be posted in the Auctions section its self, outside of any sub-forum.