Opinions on Bulletproof products?

I see their coffee recommended here often, it looks a little expensive, but I can understand paying more for quality coffee.

Does anyone have an opinion about their other products? Some seem ridiculously expensive for the ingredients included, some seem expensive but possibly worthwhile.

Has anyone used anything of theirs besides their coffee? Their "Brain Octane" oil?

(I am not affiliated with Bulletproof in any way, shape or form, just genuinely curious)