As of the time of this writing (July 13th, 2013), these are the prices of each version of the iPod, from the Apple store in the US:

16GB – US$229

32GB – US$299

64GB – US$399

To check current prices of the US Apple store, please see:

Ipod Touch Prices

And of course, if you’re living in a country other than USA, you would need to choose your country’s Apple store here:

International Apple Store Directory