I cannot provide much insight into the East Bay areas as you specified, but I will certainly comment on the peninsula in hopes that perhaps other buyers are looking for this information in those areas.  As Simon stated, just looking at sales to list price percentages are not a very good way to determine an offer price or how to negotiate.  Whether somebody lists a house at $400,000 or $600,000, it still has the same end value and is not determined where it was listed.  Certainly, there are strategies for listing agents to draw more interest with a lower price to result in multiple offers and potentially a higher end price.  That being said, the buyer is ultimately going to set it's value. However, stats are certainly appealing to look at and to use as a part of your considerations when pricing an offer.  

In the peninsula, there has been a trend in the last few months of banks beginning to price houses more aggresively.  This is resulting in quite a few multiple offer situations with bank owned properties; thus, some sales prices are going above list price.  I had a client write an offer on a property a little while ago in San Jose that had over 80 offers!  This is not the normal amount of offers, but I see 10-20 offers on a regular basis with well-priced REOs.  Though, there are certainly ones out there that will sit for awhile if not priced correctly.   When considering list to sales price comparisons, you not only want to consider the sales price compared to the most recent list price but also consider the sales price vs the original list price (before any price reductions that may have happened).  I pulled this data for San Mateo county, which included all single family bank owned properties that sold in the past month.  The sales price was 98.33% of the list price.  However, the sales price was 92.41% of the original list price before any price reductions were done.  The numbers were 99.99% and 91.88%, respectively, in Santa Clara County.  As opposed to looking at just how the list prices and sales prices compare, what I actually extrapolate from this data is how banks generally handle their pricing and what types of offers they will consider.  Certainly, for those that have been sitting for very long periods of time, the banks may be willing to negotiate greatly.  In general though, my experience has been, and as supported by the data, that most banks are not willing to sell for much less than 5% of list price. They would rather let it sit a few weeks, reduce it a little, see if any new interest generates at that price, and if not then the cycle starts again.  This continues until the price is the right list price that a buyer offers near list (definitely not saying you can't negotiate some though because you certainly can!). 

Best,

Jim Holt