It seems (and I've thought this for a long time) that IGOS books mention as many IGOS products as possible in order to encourage people to buy more. Some even go so far as to imply that the current book won't work without certain official IGOS products and materials.
Of course, that's a bunch of shit.
But it does give me pause: you really don't need anything to do your magic beyond some houshold items, commonly available herbs, talcum powder, mineral oil, incense, and some candles.* Maybe you want to spend money on a human skull or some kind of fancy pentacle. Whatever works for you and gets you going. But do you need the special annointing oil (grapeseed) made by the trained cabal of IGOS alchemists (someone's bored chainsmoking auntie) in the sanctum (basement) for an 800% markup? Unlikely.
*Or even: nothing but your body and mind.