Right, but they went immediately for it. That doesn't mean they couldn't have paid more. Also, at 20 mil they thought they were getting a deal and by buying out immediately they prevent themselves from losing a bidding war. Also, just because people post buyouts of 30mil or more doesn't mean they sell for those prices. They get bought at those prices rarely.
Case in point:
http://www.belltreeforums.com/showthread.php?161339-Marshal-Marshal-s-picture&highlight=marshal No one even bid ten million for marshal here. On the Reddit topic he capped at 10m.
This topic, the buyer was being nice. The top bid was 8m, 15 if you count the late bid.
http://www.belltreeforums.com/showt...mug-Squirrel-Marshal-s-pic!&highlight=marshal
Capped at 10m before the OP lost the villager:
http://www.belltreeforums.com/showthread.php?132731-Marshal!&highlight=marshal
Ton of bidding, capped bid at 13m:
http://www.belltreeforums.com/showthread.php?225520-Marshal!/page2&highlight=marshal
To be fair, this auction the buyout was reached at 40m, but the bid for most of the people involved was between 10 and 20, and the person who bought out was being generous to another noobie, and not buying for himself:
http://www.belltreeforums.com/showthread.php?134557-Marshal!/page3
Here's a buyout at 30m, but it took an hour and six minutes for this to occur, not 2:
http://www.belltreeforums.com/showthread.php?181002-Marshal!&highlight=marshal
Exhibit B: Let's compare to recent stitches auctions.
Bought out at 20m:
http://www.belltreeforums.com/showthread.php?134770-Stitches-DONE&highlight=stitches
Way undervalued at 5m: Bought within a minute. Someone even tried to bid higher to prolong the auction.
http://www.belltreeforums.com/showthread.php?181691-Stitches&highlight=stitches
A 15 minute auction with people fighting over who can pay 8 million:
http://www.belltreeforums.com/showthread.php?95375-Stitches!/page2&highlight=stitches
And last but most important: a 30m buy out LESS THAN one hour after topic post at no other than 30 million bells, the same as Marshal, just quicker to go.
http://www.belltreeforums.com/showthread.php?221870-Stitches&highlight=stitches