>>10716550yeah been using buyee for years and it's excellent. their regular promotions usually cancel out the fees and then some. sometimes its a % of the item price, sometimes they straight up waive the fee, so keep an eye on their coupons page. there's additional cover for item inspection and/or insurance but you can go bareback and waive it as it's optional
picrel was my haul before last, averaged out very well (AUD). prices on mercari and paypay include postage within japan, but yahoo auctions get really fucky and can double your cost, so i usually stick to mercari only
there's a sweet spot to it, if you get like 2 things you can fit more in the same box and pay the same freight charge. obviously weight is also a factor so getting like 20 things probably isn't cost effective. also, if you get something really long/wide it can spike the charge due to the dimension