While I'm not completely opposed to the idea, it'd have to be properly implemented.
There'd have to be some kind of "Galnet Auction" option, which was available at every station.
People could submit stuff (ships and modules) for auction at any station and then there'd be an auction held at a set time every week and, again, you'd be able to bid from any station, anywhere.
It'd have to work like that to prevent it being used for "gold trading".
If it wasn't a "universal" thing, you could offer to pay me, say, $20 for a Cr1bn Corvette, we could meet at some obscure station and then I'd put it up for "auction" for, say, Cr100 and you could buy it.
By making the auctions "universal" it'd mean every item would go for whatever it was worth in in-game credits and nobody'd be able to flog stuff for real currency.
*EDIT*
TBH, the new engineering system has pretty-much killed the need for auctions because now there aren't any "super-rare" mod's that people might be willing to pay silly money for.