For example:
If the items costs 100USD and domestic shipping is 6USD, engtaobao will charge you 6.36USD service fee.
(100+6)×0.06 = 6.36USD
If the items costs 10USD, and domestic shipping is 3.6USD, engtaobao will charge you 5USD.
(10+3.6)×0.06 = 0.82USD <5USD