I recently came across a Yahoo auction and Mercari item that Buyee would not let me purchase. I gave Neokyo (https://neokyo.com) a shot and things went pretty smoothly. I used to use Celga for this sort of thing, but they have not modernized over the years, and I think their communication kind of sucks now. Neokyo definitely involved more steps than Buyee, and you have to make a deposit before bidding, but I had leftover money in my account with them after the auction, and they refunded the amount pretty quickly. I think consolidation/shipping cost was comparable to Buyee. I was able to go with DHL. My last EMS package arrived smashed, so I have been trying to stick with the private shippers. All in all, I will probably stick with Buyee for convenience and a good track record, but I think Neokyo is a good option if Buyee is not available.
Good to know; I’ve come across several mercari items buyee flags as “Sorry! This item is currently only available in Japan.” And it’s a head scratcher because, you know, that’s exactly why I’m using buyee…