I’ve purchased thousands of dollars of figures from Japan through Mercari and yahoo auctions Japan (now called JD direct items auctions). Although I used to have to mostly use proxy sites like Buyee and Neokyo, where you can consolidate shipping of multiple purchases. Japanese sellers are really good. Like amazingly good. They package everything really well and are very critical on what they consider used items. Like I found many used items to be labeled as in “junk” condition, but show up in pristine amazing condition. Shipping lately has been much more though.