The lower price for ST is all due to Millwall as they have set the prices and must by FA regulations provide the same pricing to visiting fans for similar seating.
As the allication is unlikely to reach non ST what's the issue
The fact that the rain/snow came ahead of the game meant that many that had seats towards the front decided they didn't want to get cold and wet and moved to drier areas under the roof.
Maybe the club should look at CCTV footage of those at the front and reliving the Withdean experience and...