+1 for the idea, I think it has been already proposed something like that (but now I can't find the thread).
IIRC it's been proposed a few times, this one was the most recent.As I said there, I don't think that it should be split up that specifically. I think it should be split up similar to the Goods section of the forum, mainly Digital Goods and Collectibles. There are very few auctions that don't fit into either of those subtopics, however the majority of Digital Goods would be made up of Auctions (as you suggested).
This would also leave the Auctions forum its self open for any auctions that did not fit into those sub-sections. However, these other Auctions would be few and far between, which may be a problem.
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