That link just shows you how to get the DLC using Bioware points.
"Learn how to download your downloadable content (DLC) for classic Origin games, Crysis, Dragon Age, and Shift 2: Unleashed, and buy DLC for Mass Effect 2 and 3 using BioWare points."
NuffCatnip: 800 Bioware Points used to cost 8€, now they're at 10€.
While the DA: I DLC's have been on sale countless times I can't buy 7 year old content packs because these fuckups still use such an outdated system...why couldn't a different publisher buy Bioware, why?
Bioware points were cheaper to get through the Mass Effect 2 website, but they made them harder and harder to get through there until they just removed the ablity to get it through there.
DAI doesn't use Bioware Points. It's DLCs are avaliable directly from the Origin Store.
(I assume from I you ment Inquisition, if you ment Dragon Age Origins, then just get it from GOG or the Ultimate pack from the Origin store.)