This is a fairly minor bit of news, but it’s a benchmark that’s at least mildly noteworthy. Kokoro Connect was rereleased as a full 17-episode series in both BD and DVD formats on March 14th, 2017. The TV and OVA series had previously been released in separate collections. This particular collection is noteworthy because the DVD version has thus far gone unranked among products on amazon, indicating there have been zero preorders or purchases of the product. The initial price was the MSRP of $60, but, on the 17th, the price was cut by 33% to $40. On the same day, Amazon began listing that there were 5 copies remaining in stock, and the collection remains unranked. So there you go, one solid example of how much DVDs initially stock on Amazon. It may not be indicative of the overall market as a rerelease, but this minor discovery takes us from 0 datapoints to 1.
I may be able to analyze data in the future and see how typical this is, but there isn’t much point in going back to the past – I don’t currently grab “only X copies left in stock” messages, since they appear inconsistently.
Animetics 
Interesting, if somewhat random. Although it’s possible (likely, even) that they would stock more of products that had preorders, or had more originally which were then returned when they realised people weren’t buying them (which is itself likely at least partially their fault as they are selling the two parts separately for less than $60 in total).