Market Discussions

I traded some items and even made some ISK out if it.

Rules of thumb:
New items are usually bad to flip, because they drop in value quite fast.
New items are often a profitable way to turn AUR to ISK (you know you can buy AUR with ISK, right?).
If you manage to grab an item that is discontinued, you're about to make profit (if you wait long enough).
Apparel sells slooooooooow.

I figured it was very much a niche product that moves slow as they are never destroyed. I made a tidy profit on the blue Quafe shirts but I held them for a year or so.

Yes, some are bought in the NES shop (you can open it to see which ones are available) and then enter the market - for some people it is simply a way to get Isk out of Aurum..
But many are already discontinued and those just recycle in the market when owners get tired of them, but slowly becoming more and more rare.

The items you linked above aren't limited edition - they can be bought using FW L.P.

Yes, the these particular ones can be found on the Gallente Federation store. The issue of the Art of New Eden is limited, however.

Finally sold the last of my stock, when a certain well-known corp adopted a dress code.