Like others have suggested, wait if you can. If you can't, I would get the 5S either used from Craigslist/eBay (with tons of research on the device before you buy to protect yourself and your investment) or get it on a 2 year contract from Wal-Mart, which I believe is selling them for $99 on contract last time I checked (this may have changed).
All depends on your needs and your budget. The 5S is a fine device.