I decided to order a pair of slippers, worth $30 and $70.
When those arrived, myus declared them worth $30 and $600 respectively. I immediately contacted them with the description of the mistake, but they shipped the package anyway, charging me $60 for it.
Our border controls held the package and - because the price declared was much higher than the slipper price, they didn't let it though. I again lost $20 for brokerage services.
I contacted myus support with this, and what they told me is that they are going to charge me for return shipping, and than for the shipping again.
If you considering whether you would like to use them, think again. It's not worth it.