The meta-alloys one is unique, but the Palladium ones are very common at the right stations. High-Tech stations tend not to be as good - as 777Driver says, it's about stock levels, and most of the high-priced goods in most high-tech systems get driven down to low stock by normal passing trade. Extraction economies out on the fringes, on the other hand, are much more common, so finding one that no-one else is using for high supply levels is much easier.What the *(&()... I'm allied with all factions at my home station and have a trader rank of Tycoon. It is always in boom along with just about every system in a 20LY radius of where I am. Home station is a high tech station. I have never ever seen missions like shown on your screen - ever. You're the real deal.
(Tycoon rank is sufficient: I got from Tycoon to Elite pretty much just by running these sorts of missions while trying to get to Allied with a bunch of local factions)