If you're in the UK, you'll see there's now a 'View <n> reductions at Play.com' item in the menu which links to a page that'll show you what's currently reduced at Play.com.
Items that they offer, including those in their third-party marketplace, are also shown under the 'For sale' tab on individual set detail pages, e.g. this one.
Hopefully, this'll be useful for someone.
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