How much does a bit coin cost?
You've asked about five different questions here.


This is a standard scam and there is no reason to think they actually have anything.  
There is no way to trace the owner of a Bitcoin address. That's why these scammers ask for payment in Bitcoin.  
The cost of one bitcoin varies continuously, just like stock prices or currency exchange rates, but you can easily find the current exchange rate by Googling for something like "current bitcoin price".