i buy from Japanese resellers a lot. as long as you do your homework and authenticate before purchase you are usually going to be ok. and i stick to only resellers with a strong history of sales of authentic items. and if they have a long-standing online business with contact information and etc. i look for the same things with a Japanese reseller as with any store/brand. a history of sales, reliable contact information, and some English-language skills help, too, in case of a problem. i have purchased from Japan maybe 8 times and every item has been authentic and in better condition than described - their interpretation of 'poor condition' is closer to 'very good.' they seem to err on the side of caution. you do have to wait a long time for items to arrive through customs, especially during peak mailing times, and custom fees are random, but can be high. in 8 times i paid once, and it was a hefty $100, making the bag not such a bargain. don't be afraid, but be smart before you buy

my first purchase was about $100, in case i made a mistake or it was fake... keep that initial purchase very low imo, to 'test' what you're doing before jumping in with a crazy 5K purchase or something.