How much will they charge? Approximately... Do they charge per bitcoin? Or an exact fee for a transaction of any amount?
It's been a couple of months since i used them, but i think it was a percentage... So you would deposit the coins for free, pay a percentage fee to exchange USD to LLD, pay a percentage fee to exchange LLD to BTC, and pay a percentage fee to withdraw the BTC.
If my memory serves me correctly, the fees were ridiculous... A number of +10% is stuck in my head (the 3 fees combined). The more often you use them, the lower the fees will get (also from memory).
Once again: i didn't verify this, virwox is rather transparant fee-wise, so you could easily look this up to make sure my memory served me correctly!