I've seen this in trade forums and a few times in game while browsing for deals. With inscriptions, purple items can now be modded to have perfect stats. However, despite that I still see, "It's purple, it's not worth as much." Inscriptions makes the item color, gold or purple, somewhat irrelavent objectively, but some traders don't seem to see it that way. I sold a perfectly modded purple spiraling spear recently, but for far less than it probably would have been if it had gold text.
The most that gold or purple would have any influence on a purchase, imho, would be if it's unidentified. Unidentified purples are pretty much guarenteed to have nonperfect mods. Why do some people persist in this-now artificial distinction, when only the item skin should matter?
(Of course, the purple/gold items described here are NF only. Pity. I wanted an inscriptable Mursaat hornbow.)