This table indicates overall production costs for an item with a given Coefficient. These values include a large number of low-level reagents and materials that would be required throughout construction, but are common enough that their availability can be assumed without a problem. They do not include the cost of the base item, which must be created or acquired separately.
This table can be used to estimate an item's market price, for example by tripling the listed prices; however, the sheer rarity of high-level items means that truly powerful products are virtually priceless. It would be highly unusual to see an item with a MC greater than 5 for public sale.
That's where I got my info from...directly off the Magecraft part in the lore. The way I understood it is that there are reagents and Reagents. The lowercase reagents are things that Tarot didn't put in the write-up...unimportant reactive substances and materials that should be fairly easy to come across...but expensive to purchase. So even the lowest level MC item still requires a lot of ingredients to work. it's when you get up to needing Reagents, that you can't just buy them...but have to find them.
That was my understanding anyways.
