I never did finish writing up all of the Mint stores in Tokyo, but I just revisited Mint Ikebukuro this weekend, and they have a MAD sale on old boxes of packs. I got a box of 2002 Preview (15 packs, 8 cards per pack) for Y597, and a box of 2003 2nd Version light packs (20 packs, 4 cards per pack) for Y630. They've also got a ton of great interesting game-collected stuff now -- including a series of Lawson's cards that are only available at the Sapporo Dome, apparently. I couldn't justify buying them at around 800-1000 per card, but they featured things like the 9-man hero interview, funny pictures of guys like Kensuke and Naoto dressed up as chefs, special cards for the cheer girls and other Sapporo Dome things, and so on.
Also, if you want collated sets of some of the recent boxes, with no insert cards, you can get things like the Seibu 30th Anniversary regular cards for Y1260. They've also got the Tokyo Big 6 College set, normally 2000 for all 6 teams, broken out so you can get each team's set for Y450 (but of course they had none of Waseda and Rikkio). I also poked through the Hakata Lions historical set (which is only worth it for the Inao cards IMO), and they also had the Johnny Kuroki set collated out for... I forget, it was like 900 yen maybe. Oh, and in further awesomeness, they had IBARAKI GOLDEN GOLDS CARDS! I wonder how hard it is to get one of Ayumi Kataoka...
And if you are a Tigers fan or Baystars fan you can look through the ridiculously cute little figurines they have. It's 315 to buy a box with one unknown one in there, or anywhere from 400 to 800 yen to choose the one you want (though to be fair, they didn't have any Kanemoto or Miura or whatnot, so it might get more expensive for those guys):
Also, I need to sort of take back what I said before about the proprietors there, because the guys who were there on Monday when I went were really funny. (Plus when I told them I hate the Giants and have cards/etc from the games, they were like "Please bring it here! We are happy to buy Giants crap from Giants-haters!")
But if you're looking for packs of cards, I would actually suggest going to Mint Akihabara, of all places.
Location: 東京都千代田区外神田1-15-16 秋葉原ラジオ会館2F (Google Map)
Tokyo-to, Chiyoda-ku, Sotokanda 1-15-16, Akihabara Radio Kaikan 2nd Floor
Hours: 11am - 8pm, every day
Directions: Exit the JR Akihabara station for Akihabara Electric Town (the west side). Take the south choice of the two exits on that side, and Radio Kaikan will be right across the street. Go up the stairs to the second floor and turn left, then right, and you should see it. (There might be more than one stair, though.)
Size / Type: Mall store. Small.
People: Eh. I actually think I heard them talking about me, but I am used to ignoring it now, so maybe I was just imagining it.
Stock of interest: Not much, BUT, they have TONS OF PACKS ON SALE. AND MAJORLY ON SALE AT THAT. LIKE 15% OFF SALE.
2008 BBM 1st Version packs were going for 178 each, as opposed to the normal 210. That's just crazy mad sale. Team packs, normally 420, were selling for 357. They had the Tokyo Big Six box set for 1800 yen (10% off). They also had boxes of team packs and of the normal BBM packs, though I forget the price exactly. It was a good price, in the 25% off range, IIRC.
On the other hand their prices for single cards was retarded. Stuff that would be 50 yen, or 30 yen, or even 10 yen at other Mint stores, was all in the 80 yen - 200 yen range here. And their collections of single cards was terrible. The only funny part was that I found an I.D. 1993 card of Takuro Ishii for 30 yen. The guy had this look of "Why is this so cheap?" combined with "Why does this crazy American want it?" when I bought it.
Also, the store is like 80% gal cards, ie, the cards of women in bikinis and stuff like that. Then 15% is soccer cards, which leaves like 5% for baseball.
Basically, I think the reason to go here is if you are already in Akihabara for other reasons and were thinking of picking up packs of baseball cards, you can get a pretty darn good deal.
Now, if you live in Saitama, I would highly recommend Mint Urawa or Mint Minami-Koshigaya. Koshigaya for their prices, Urawa for their INSANE awesome stash of cards which I still haven't finished going through after 3 visits.
Location: 埼玉県越谷市南越谷1-15-1 南越谷オーパ4F
Saitama-ken, Koshigaya-shi, Minami-Koshigaya 1-15-1, Minami-Koshigaya OPA 4F
Hours: 10am - 8pm, every day
Directions: From either the south exit of JR Minami-Koshigaya or the east exit of Tobu Minami-Koshigaya, go through the taxi turnaround and all, and turn left onto the main-street-seeming road (go past the pachinko parlor and the restaurant food court mall on your left). After walking a little bit you'll see a drugstore on your left if you're on the right street. Go two blocks -- they're two long blocks -- and you'll see the OPA mall kitty-cornered to you. Go in there, find the escalator, go to the 4th floor, you really can't miss this place.
Size/Type: Mall, but BIG for a mall store, relatively
People: Nice, friendly guys. I even forgot my point card there one time and the guy made me a special receipt so I could get my point card stamped the next time I came in.
Stock of interest: EVERYTHING IS CHEAP! Packs are all 10% off! Box sets are usually majorly discounted too! And single cards are almost free!
The selection is kind of crappy, but depending on what you are looking for, and when you go, you can get some amazing deals here. Single cards from most BBM years are only 10 yen. Even from THIS YEAR, assuming they aren't popular players. (I got the "Goodbye Yukio Tanaka" card from the 2008 BBM 1st set for 10 yen.) Think about that -- a pack of 8 cards costs 189 yen there, but you can get 8 cards for 80 yen. Crazy, huh?
However, most player single cards from this year are 31 yen, or 100 yen for more popular ones, and so on. But still, if you are trying to collect a few obscure guys or weird farm team guys, you could really luck into some stuff here.
And the box discounts are nuts. I got the 2006 Nippon Series box for 1313 yen there a couple of months ago (50% off the normal 2625). Got a Fighters Spirit box, minus the insert card, for 700 yen. There were other boxes there for equally insane prices too.
I would recommend going to this place if you live close enough that it won't cost a ton to get there by train, or if you'll be in the area for some other reason (I can't really think of why, though; I usually go there on my way there or back from Chiba or Kamagaya since I take the Musashino-sen). The pack and box discounts are pretty awesome, but it might not offset the crazy cost of getting out there.
I'll have to write about Mint Urawa some other time (and Mint Hachioji, Tachikawa, Yokohama, Fujisawa, Komagome) when I'm not dead tired.
Today I'm going to the Marines-Dragons game in Chiba! Exciting! I hope it stops raining, and I hope the starters are Masa and Komiyama, because they both turn 43 later this season, and I really want to see a Masa start before it's too late. (The other thing I want to see in person is a Kenshin home run. I doubt that one will happen.)