First link is bootlegs, don't bother with that crap.
There's been 3 different release of the Rurouni Kenshin TV series- singles, Wooden boxsets, economy boxsets. No matter which version you get, the discs are all the same- only the packaging changes.
The economy sets will likely be your best bet. Waiting for a Media Blasters sale at Rightstuf will allow you to get all 3 for $150. You might try finding someplace with the wooden boxes on a closeout price (since they're OOP), but I wouldn't count on it. Collecting used singles might go a lil' cheaper, but the effort involved would really cut into the "value".
This is all just for the TV series- I'm not familiar enough with the OAV/TV releases to provide much help there.