I personally haven't found a place to buy them, though I once found them in a wreck. (so buying them probably isn't possible) Try looking at the threads in the Spoiler Forum, maybe you'll find something there.

However, you can buy Screamer Mines in one of the Omicron Systems (can't be more specific or else it'll be a spoiler). They're almost as good.

You can't. You can buy Ripper mines everywhere, assuming that you have high enough level. But to get the Ripper mine launcher you have to desecrate a graveyard that is patrolled by evil translucent Cerberuses with very powerful guns. I recommend at least a Barracuda, but it has been done in smaller ships.

For details have a look at the stickies in the spoiler forum.

You mean Nomads right?

We who are about to die salute you!

Again, try the spoiler forum.

If I had a nickel for every time someone told me that my idea for melting down coins to make a giant robotic parrot was a bad idea, I would have one kicka$$ giant robotic parrot.

its been that long I dont even remember where I got my Ripper launcher from...

although I must say recently I've been coming round to thinking that expensive mines are pointless, I usually only use them for shaking enemeies off my tail in which case a drone would do, or plonking around bigger targets like capships and bases, which torps can do better. I wouldn't be without mines they ae useful but I'm not really able to justify the expense considering how many I chuck out largely just as explosive decoys.