Wing did reasonably well until they flooded the market. Same thing happened with G-Gundam. UC stuff has historically flown off the shelves reletively fast except for the somewhat unpopular figures like the Zeon Amphis and some of the lesser characters.
But UC stuff has not been brought over to the extent here as any of the EU stuff has, and therefore the EU stuff sits and collects dust. I can walk into a store and expect to see tons of battle damaged G-Gundam POCs, as well as regular G-Gundam figs, the big ones they made, G-Gundam model kits, etc. Every now and then I'll stumble accross the occasional UC deluxe set (Gouf Custom, that sort of thing) but very rarely now. Generally model kits don't sell well either (understandably).
It reminds me exactly of Star Wars figures... The ones you wanted (in my case, UC stuff like Zakus and etc.) are nowhere to be found because they're short-packed or super-popular, while the crap (ugnauts anyone? lando calrissian? ep1/2 figures? G-Gundam, battle damage and Wing Gundam?) sit and collect dust going nowhere.
And trust me, my hate for G-Gundam goes way deeper than my hate for Wing Gundam. Some of the Wing Gundam designs were actually good.
Vostok 7