I use Buyee to purchase K-Pop goods through Mercari Japan. Buyee makes it incredibly easy look for items and purchase them. I first started using Buyee in 2018 and now a lot more frequently in 2020. They are always having promotions for waiving service fees or discounts on international shipping, so look out for those as well! Overall Buyee is incredibly easy to use and a great proxy service. I definitely recommend using Buyee. If there are problems that arise, their customer support staff is AMAZING. Everyone I've talked to has been quick to answer, polite, professional, and genuinely nice people.