Buying Key Codes

I just wanted to know if its a good idea to buy a code in-game, is it safe to say, buy a Factions code from someone in Prophecies? I see people wanting to buy codes for 100k, is it a safe transaction though, or would you just be throwing away 100k because the person may take the money away. Also, how would it work? You cant just give them the money and hope they give you the right code.

It will never be safe to buy a key in-game. Not only that but you're also not allowed to do it.
If you're caught you will be banned.

Yeah, it's against the EULA to buy a key in game, it's impossible to know if the seller is honest anyways and as smile said, you'll get banned for this if anet finds out.

NO! It's a very bad idea to buy a key-code from someone - unless it's the local market that is selling an UNOPENED, brand-new game. Either you'll get one that's already in use, or you'll get an invalid line of letters / numbers. in either case, it's a scam. Then, all you can do is nothing. Can't report the scammer, because YOU'RE violating EULA rules, so you'll get banned, too.

To transfer a key (via trade or selling) to someone else is also a violation of EULA, too. Those people you see offering to buy them are probably bot farming outfits who are selling gold on E-bay or whereever.