Does anyone know how to check the recorded sales prices for properties in San Berardino County? I feel like it should be here somewhere, http://www.sbcounty.gov/assessor/pims/(S(j1gyavnut0o0xcy05pxcant0))/PIMSINTERFACE.ASPX , put the APN in the top left in Parcel Inquiry, and then find the info in the data below, but I can't make sense of it. Perhaps it's on a diff website? I'm not looking for sold comps, but the sold prices of specific parcels.
There are a number of places where you can get past sale prices in California (including, but not limited to S.B. County) - these include public records, the MLS (there are actually several, but the CRMLS is probably your best bet), title databases (from title insurance companies), and third-party systems.
These all vary in terms of how complete they are, how much they cost to access, and in the case of the MLS whether you need to be licensed to access it. Public records (as per your link) is the source I'd recommend the least, for a number of reasons; they may be free, but the data is a challenge to get and use.
The most reliable free source I know for this information is a title database. All title companies have their own databases which collect all the public records information and make it searchable. In addition to being free, title databases are also one of the most complete sources you can find; this is both an advantage (since they include sales not made through the MLS), and a slight challenge (since they also include inter-family and other non-arms-length sales which don't help for most price research). Most title insurance companies will give you free (though sometimes limited) access to their title database if you're a real estate professional. So to get access to a title database, develop a relationship with a title insurance rep.
The main limitation of title databases, though, is that you're often limited in how many title reports you can pull, and there's often no way to do searches of lots of properties at once. For that, you might want to consider paying for a third-party service like Propstream. These often also have some quantity limitations, but it's usually much higher (Propstream allows unlimited searches, and allows you to save 10k properties/month), and these systems also usually allow you to export the data (so you can do things like import it into a spreadsheet and run calculations on it). I'll be very honest that I'm a big fan of Propstream (I use it all day every day), but I have no financial relationship with them, and I'll make no money if you use it based on my recommendation.
All that said... I do alot of data crunching of property data in S.B. County myself (price is just the tip of the iceberg), and I have access to all of the types of sources listed above. If your needs aren't too heavy, I can probably pull some data for you and maybe do some analysis for you; in fact I already have a number of reports which do some deep dives into pricing, so I might already have some of what you're looking for. I can also refer you to an excellent title rep in S.B. county who'll probably be happy to give you access to a title DB (again, I make nothing from referring you). If you're interested let me know.