14
Based on my experiences meeting other Trekkies at Phoenix Fan Fusion and Tuscon Comic Con.
Like, once you get past this part, most of the original Trekkies are fun to talk to, but combined with that subset of gen X TNG guys who talk about their college years and give you unsolicited life advice while probably a bit inebriated, you probably lose an hour at whatever convention to hearing this same flex over and over again. 
Also, yes, at Fan Fusion I found out Gen Alpha Trekkies do exist; saw one wearing a DS9 uniform commenting at a panel.
Wow. That's absolutely nuts considering that's about the cost of an entire series Blu-Ray box set now!
Were you having to import them or something? I was almost tempted to do a similar thing and import Doctor Who Blu-Rays from Germany for post-Tenant stuff at $120 a doctor since BBC America had only done very small runs of the doctor box sets stateside, but now they're reissuing them here for $35 a doctor, for which my wallet is thankful.
No these were the official local releases for Region 2 and Region 4 (Europe and Australia/New Zealand) They were shaped like Photon Torpedos, there were 7 released for TNG, and then same again for DS9, VOY and ENT. I believe the came out a year or so before the US started getting them, but I cant remember. I still have all my Torpedo sets in a box. I rebought what has come out on Bluray too, as I am a completionist when it comes to trek