Oh -
that stuff.
I saw some a couple of weeks ago in the Libby Mall supermarket, (Jl Teuku Umar, Denpasar). There was a pile of it, (in the small "imported foods" section) and I remember thinking to myself at the time how many local Balinese would actually buy it.
I
might have seen some in Hardy's Sanur a few days ago, whilst searching for the currently elusive Vegemite. (I have irrational cravings, too). The Pantry (Sanur) is also worth a try...
I spotted a 400g jar of Vegemite at Pepito's for about Rp250,000!
Macaroni is easy to cook. Kraft cheddar is readily available. Cream, butter and MSG are easy to find. A teaspoonful of Vegemite in the mix should sort out the Vitamin B "content".
If you can't find "the real thing", do it yourself. The nutritional content of your own concoction might even be higher than Kraft's, despite Kraft's claims that their macaroni-cheese has more than the actual cardboard box it comes in.
This suggests to me a small business venture for somebody. A depot somewhere that only stocks foodstuffs that foreigners crave. I can envision a back-room somewhere piled high with Mac-cheese, Vegemite, Promite, Marmite, Cranberry sauce, etc. Buy it all up when it's available, sit back and wait for desperate addicts to come beating down the door.