Interesting.
I have one suggestion -- don't lose it in the lights. Keep in mind what the original objective of this exercise is -- helping people pass ROFR.
I'd keep the entire listing here, as Beca has done for the duration...and then provide the link to your database. I think the database is very helpful to people who feel comfortable sorting and filtering, but many people aren't. There are also a lot of people who won't even realize they are supposed to click on the link. Those folks will look here, not see anything of value, and wonder what all the fuss was about.
Also, with regard to Beca dropping the earlier data, there is another reason why it makes sense to do that. ROFR is a constantly moving target, and what happened six months ago is probably not relevent today.
While a larger body of data might be intellectually interesting, a lot of things have changed in the last few months, and including old data may actually hurt people buying now.
People are not looking for statistical data, they are looking for the price they need to pay today to clear ROFR. My $73 at OKW passed in Feb, but if you think you'll pass today at that price, you are probably living in a dream world.