About a month ago we rolled out some new pricing code. In a nutshell, it lets us more accurately track prices of retailers, and do so at a faster interval. It's been a long time coming - basically been in dev mode hibernating for about a year. It's a critical part of reusing pricing for other use cases...
Anyway, the code is mine, and so the bugs are mine too. We do some internal things for performance reasons to not thrash the database on price updates. I botched part of it, which caused many prices to think they didn't need to be updated for a very, very long time. Like, oh, several decades. Doh. That effect took place this past Friday right before I went out of town to the land of almost no internet (went to my Mom's place to build/frame a new roof for a large shed). So arriving back in Austin yesterday I found that price drops had stopped working, and the culprit was my pricing bug that got activated last Friday.
I identified and fixed the bug tonight, so all should be back to normal. Price drops are showing a bit abnormal, but should return to normal here in about a day. My apologies for the lack of price updates during the last few days. (Quick note - Amazon pricing takes a different code path and wasn't affected - their prices were updating properly the last few days.)
On a positive note however, the changes pushed live last Friday did have some good stuff too. We improved our ability to match up products in our database with retailers - to the tune of an additional 16,000+ retailer match-ups added to the site. The bulk of those ended up in non-US locales.