I don't know the multipliers (LA Guy has a better idea on this topic, and I think Fuuma does as well) - but basically the Asians an the Japanese in particular have normally sold domestically through direct sales and then it's hard to make a case for selling their product via third-party boutiques.
In addition, the labor in Japan for Japan-made stuff (and it's either old Japanese ladies most of the time for the really quality, unique things, or probably third-world immigrants for big mass-produced MIJ stuff) - it's more expensive than even Made in Italy (where it's all Chinese people or gypsy types who work for less than you'd think, considering the price of the items). IN addition to that, most stuff besides YKK zippers and maybe some domestically tanned calf and horse plus Japanese cupro lining, the rest of it is imported, whereas maybe the Italians have a domestic source for these things. tl;dr: Japanese stuff costs more to make, is priced lower.
That was the way it worked for a long time, now you see makers like Visvim breaking onto an international stage and they're having to raise their prices into the stratosphere so that they can offer wholesale prices that don't require a foreign boutique to basically buy at retail. They could've lowered the quality but that wasn't an option, in their position. So, the price went up instead. They make more money on the domestic sales floors and then they have a wholesale price for foreign shops where they're not giving the product away to saturate the market for little to no return.
My guesstimate for Japanese brands that use the old model and not the Visvim 'raise prices lol' model - I'd say the markup between item cost (labor and materials, shipped to the store, plus taxes in) - they might mark it up by like, 3-5 times? Maybe Julius gets the product tagged and bagged, shipped to that black Daikanyama store and they slap a price that's about 4 times the cost of what it took to make the jacket and then the rest is profit. That's why all the Japanese leather jackets used to be in a similar price range if they were of similar materials - lambskin jackets were like 158,000Y and cheaper leather was like 118,000Y - it was that way for years and still kind of is. There is just a market price to make and sell leather jackets because the manufacturing and wholesale base is small and they use similar materials.
Western-based manufacturing, I think since that stuff is not always for Italian brands and therefore product travels several times and gets touched by a number of people, the markup from cost (labor, materials, shipping, tax in) to retail tag price, the markup is probably like 10-20 times of that cost. The 'brand' doesn't make that much since they're just wholesaling. An MMM 5-zip leather jacket might cost like $150 to make and then they mark it up to like $1000 for wholesale to boutiques, and then boutiques mark it up to $3200 or something. Tons of useless hands in the pot when it comes to the old-world retail model.