I was actually curious about this subject earlier and looked into it. Shawn released the US AES production numbers for early games, but evidently SNK/Playmore didn't want that information to be released and Shawn had to abide by their wishes to keep the games coming (the indications were SNK/SNKP were embarrassed by the small size of the production run. Seems even for SNK/SNKP "size matters" even though it's a silly position to have since it's for a market they treated as a backwater 1+ years after they entirely pulled out of it and hadn't treated as any kind of priority in the 6 previous years from 2001 so of course it would have small numbers, not to mention the US not supporting older consoles as long as Japan does [e.g. compare how long the SNES, Genesis, Dreamcast lasted in Japan vs. US]). The only confirmed numbers I could dig up...
Metal Slug 3- 500 copies
Sengoku 3- 500 copies
King of Fighters 2001- 500 copies
Metal Slug 4- 300 copies
Rage of the Dragons- 300 copies
Shawn was told by SNK/Playmore early on that production runs of 500 were needed to secure the orders, at least initially. Some games moved like snails with their large stock (Sengoku 3, KOF 2001), so he was able to reduce the orders down to 300 so he wasn't stuck with so many carts.
For the rest, it looks like Matrimelee had 300 copies. It's not clear if they ever went below 300 (would Shawn be willing to reveal what the smallest production run was for a late AES release, even if not pegged to a game?). Looking into it, some games *might* of had something over 300/under 500 produced (400? 350?) like SVC Chaos, which looked good to many in the lead up to its release, but hideous after its release (I guess SVC Chaos was a bakkushan). MS5 did sell out extremely fast, but not sure if that was because an order under 300 was put in or because of high demand (Metal Slug had the highest demand from 01-04) combined with knowledge it was made by SNKP and not a Korean substitute as Playmore needed as it reconstituted itself.
My best guess with some of the others based on listed preorder totals I was able to dig up (and with hints like no game had under 70 preorders [Sengoku 3 had 70 preorders])-
* King of Fighters 2002- Shawn once said KOF2003 & 2002 had the same number produced. Maybe 400? Or was it 300 with significantly reduced demand?
* King of Fighters 2003- 400? Numbers were hidden until months after release of remaining stock. Definately seems like it was *not* 500. It did sell out far faster than 2002 or 2001 though.
* Matrimelee- 300. Looks like a pretty clean case for that number.
* SVC Chaos- Seems to be over 300, so perhaps 400? Maybe even 500? It had at least over 100 preorders but 500 would require too many preorders (like 300). 350~400 seems like a reasonable number for "high interest".
* Samurai Shodown V- Maybe 300?
* Samurai Shodown V Special- no clue. The whole unfixed vs. fixed division and being unable to find any fixed tallies makes it hard to track. It was likely small, 300 (or less if less were ever made).
I was also able to dig up when several of the games sold out. Sadly, while many marked the milestones of a US AES sell-out when it occurred while the Neo Geo was still seeing releases, after it, the sellouts went quietly. I tried to use that to get a sense of demand vs. supply to deduce the totals.
1. Rage of the Dragons (2003)- 2nd quickest to sell out. Looks like it took 6 months.
2. Metal Slug 3 (2003)
3. Metal Slug 4 (2004)
4. Metal Slug 5 (2004)- quickest game to sell out. Did so within a month or so.
5. Sengoku 3 (2004)- it had a large stock that didn't come down til it was aggressively discounted and people realized its use as a late-Neo Geo sac cart.
6. King of Fighters 2003 (2006)
7. Samurai Shodown V Special (2007)- Unfixed sold out early in 2007, fixed sold out late in 2007.
8. Samurai Shodown V (2008)
9/10. King of Fighters 2001 (2009 or 2010)- It had a hell of a time moving the last 100 or so carts.
9/10. SVC Chaos (2009 or 2010)- its stock moved glacially.
And it looks like Matrimelee, KOF 2002 still have some original stock left, at least best I can tell.
Would Shawn now be able to reveal production numbers or would that jeopardize getting the new Neo Geo handheld? Or, maybe more indirectly- were their any production numbers besides 300 & 500? And if any were lower than 300, what were they? And another question- what was the rough percentages/fractions of English AES buyers to Japanese AES buyers to MVS buyers during the 2001-04 run of Neo Geo releases through the Neo Store?