I dont know. I live in Canada. There is no DC for international orders. But for within Canada its $1.50 for signature.
my mail costs the following for the US.
Bubble mailers regular mail = $3.10
Bubble mailer registered = $17
Bubble mailer xpresspost = $23 (sig delivery 4 days)
Fed ex = $48
All of them have to be done from PO. I could print off the labels at home but I still have to get to a PO or a mailbox.