I have all of the official albums plus some cd singles. I also have a bunch of good quality live shows and dvds. You guys shouldn't buy bootlegs since you can get almost all of the stuff in way better quality through trading and through torrents.
If you guys download torrents, check this site out. It is almost entirely Nirvana shit.
http://onemoresolo.net/
And there is currently a torrent with 3 fecal matter songs which are unreleased. They are mp3 sourced but they are the only ones available. The asshole that has the tape won't release all of it in lossless form, he/she only released these songs in mp3 format.
Also check this site out. The amount of information it has is insane. It is a nice companion for live show collectors.
http://livenirvana.com/