From Amazon, a Musashi AISI-1060 useable katana. It's roughly $110 and includes free shipping. Also has an acid-etched hamon across the blade, which indicates they put a little more care into this sword.

Musashi isn't bad; they're a Chinese company that usually provides the swords for a lot of other resellers. Something to note: if a reseller uses a real classed metal, they'll say they use "1060" or "1095" or "T10" or the actual specification of the metal in the sword, otherwise they'll get away with saying "carbon steel" which you can assume is just junk.

If you'd like something better than what Amazon normally offers, the Budget Buyer's Guide is at the top of the /r/swords forum and is very well researched. Can't go wrong with anything in there.