I think Zenmarket.jp is a good and cheaper alternative to buyee.
They only charge 300 yen per item and you get to choose SAL shipping (cheapest option available).
And apparently they have a working relationship with FedEx hence their FedEx delivery can be even cheaper than the normal airmail or sometimes cheaper than SAL. But I'm staying away from FedEx due to their notoriety of collecting taxes for all parcel in Malaysia.