Hey Broadway World! I'm Keith, I built TicketData and I noticed your post about it here.
quizking101 - You are definitely right. Right now, the data is strictly from resale sites. There is no data from the primary box offices. I certainly agree, if there was also data from those sources, the site would be significantly more powerful for Broadway go-ers, and if there is sustained interest, I'd like to build that out (plus additional features that some others had mentioned, for example being able not just see the entry price, but perhaps the MEZZ/ORCH price for all the shows in one single list). That being said, there are indeed plenty of times where resale sites are under face, especially on non-weekend dates and on the day of the show. Wherever possible, I'm also linking out to the box when you click on any event (still needs some more work to get all those setup across all venues), so that you can easily check to see which is the better place to buy.
chrishuyen - You are correct, for historical purposes, we try to target somewhere around 90 minutes before the event as its "Final Get-In Price". This is kind of just a record keeping thing, and there's a bit of an art to it, especially with Broadway shows where the prices on resale sites can jump so much (both up and down) in the finals hours before the event. I built an algorithm that tries to pick a price that generally reflects what the prices were around that time, and tries to omit a last minute jump/fall in the minutes before the event because I don't think a one-off listing really does much to represent the actual "value" of that event.
That being said, I am certainly recording prices right up till event time, and you can see these if you click on any event, there is a chart showing the live price, event 15 minutes before show time. It's just that I wont necessarily record that as "Final Get In Price" for the historical shows (but once again, you can click on those historical shows to see the data right up till the event started).