A Lansky 5 stone system costs less than $35.
The next step up in assisted systems is something like a KME sharpening system. This costs about $115 to close to $200 if you want the diamond stones and other dodads. Then the Edge Pro runs from about $200 to $700 depending on what accesories you may want.
Powered equipment runs from the cheap 1x30 belt sander for $45 to the Ken Onion Worksharp($130) to whatever you can afford.

Back to freehand sharpening for a minute. I kinda skipped over Japanese water stones because I had a brief run in with them. I thought that they were too expensive, too messy and the ritual to use them was too finicky and time consuming. If you want to dive in to that arcane method of sharpening, you are on your own. By the way, I sharpen my katanas with a mousepad and sheet of sandpaper.

So, to sum up you can start off with a Norton combination aluminum oxide stone, oil, a piece of leather on a board, and chromium dioxide for about $35. Along with some patience and maybe a Sharpie, you should do fine. Until you start reading sharpening threads on various forums and decide you need electron microscopes and edge testers to tune up your Busse Combat MOAB.