A:
You're looking about about $699.99 USD ($4,478.54 TTD) if you were to buy the phone without regard to a contract.
If you are signing up for a new 2-year contract or eligible for an upgrade with Sprint, Best Buy currently has a sale for $149.99 USD ($959.64 TTD). Keep in mind Sprint has upgrade fees--usually about $36 USD ($230.33 TTD).
If you don't want to spend that much, the iPhone 5 and iPhone 5c are very, very similar to the iPhone 5s. Also, consider checking out the iPhone 4s.
You could always check Ebay as well...
It's a great phone!