So I collected english cards only, until worlds 2010 when I bought a box of heart gold for $38, and it had 19 packs (only one pack was sold), and I believe every pack had a holo at that time, and they had 10 or 11 cards back then. I bought a few more loose packs and blisters which I was very happy with. The price was unbeatable and every pack (I think) had a holo. I didnt get any more japanese boosters until worlds 2013. Although, in 2011 I bought a few decks, because those have also always had more than our theme decks in terms of cards, such as primes back then. And I was able to trade a collector all of my japanese primes for the english versions at the time, which is when cards such as magnezone were worth a lot, so I stopped with japanese stuff again until 2013. Except for the japanese reverse holo primes, which I think are one of the hidden treasures that I rarely find. In 2013 I was mostly just looking for the sleeves and deck boxes that I had missed out on in 2010, such as the umbreon espeon, charizard, and walking starters merchandise, which are all very rare now, and I am still searching for them. And at worlds, I had known the 15th anniversary pikachu set would be for sale from japanese players, and I only managed to get one set sealed and one pikachu full art for $5. I later realized the value of these sets, and decided to get into japanese cards. I got a few here and there, until more recently when I bought in bulk. For collecting, I think japanese is the best way by far to get your value. Instead of $90 for a booster box, buy a 12 rayquaza jumbo pack box, worth so much more than $90 anywhere besides Japan. You just have to buy enough to make shipping reasonable, so I would recommend buying sleeves, to trade or sell. The rayquaza packs contain 6 boosters and a sealed blaziken ex, so 12 sealed ex, and 72 packs. The blazikens sold for enough to pay half of the box of 12 jumbo packs, so $40-50 ish for 72 packs is what I ended up with, which is totally worth it if you ask me. And in single jumbo packs, I would open a box worth of ultras, for examples one jumbo pack contained shaymin ex fa (i got $55 for), gold switch, and mega aggron ex. These packs have about a 1/2 holo rate, and considering they are less than $2 and half size of US pack, holos/EX/SR are about 3 times more likely. This got me to buy more japanese cards, personally I dont really buy boxes, I buy these special packs, because I also sell some stuff to get my money back. I am still bigger in collecting english cards because I feel that the prices are more consistent, but I would say from only a collectors perspective, japanese cards are better to collect, except for the secret rares, which can be extremely expensive, such as m rayquaza fa from emerald break, for the first month or two. I think they hold their value decently well, especially because the cards are higher quality, and stay mint. Also Japan has cool exclusive stuff like the two pikachu sets, illustrator cards, awesome promos, and more. Hope I helped a bit, feel free to ask me anything.