It's more than 60%, it seems the Brazil customs charged twice
The first time they charged 60% of the total value(Miner value plus shipping cost)
The second time they charged 25% of the total value plus the first tax.
For example, if the miner value is $800 and the shipping fee is $200
The total import tax is : ($800+$200) * 60% + [ $1000+ ($800+$200) * 60%] * 25%=$600+$400=$1000