EzekielRaiden
Follower of the Way
What would be the default campaign assumptions used to assign values to properties? Should they produce several lists to fit different types of campaign?
Absolutely, if they're dead set on giving specific coin values to things. But there are cleverer alternatives that require less space.
For example: Create a set of terms that describe items. So, for instance, all items that allow you to float, fly, hover, etc. could be given the "flight" tag. All items that produce potable liquid (water, wine, beer, etc.) have the "drink" tag. Etc. Then, you include a section which details how items of a given tag influence, and are influenced by, the assumptions of a setting. Flight items are going to have deep effects on basically all areas of the game--and are pretty "flashy" as well, by which I mean their effects are "overt" instead of "subtle." A low-magic campaign might not have any such items at all--or, if any exist, they're more like artifacts (e.g. Hermes' Sandals) than anything else. "Drink" and "food" items (and, potentially, "shelter" items as well) are largely unimportant in a "high fantasy" campaign, but run counter to many of the assumptions of a "survival" campaign (e.g. Dark Sun)--so, again, such items may not exist, or are artifact-like (if anyone ever wanted to sell them, it would only be at fantastically expensive prices).
And then have a page or two dedicated purely to talking about different "kinds of economies" (for lack of a better term), and how those different ideas can support or undermine assumptions involved in various common campaign types (high fantasy, pulp adventure, gritty realism, environmental survival, pre-civilized/post-apoc, etc.)
You wouldn't need more than a word or two added to most magic items--words that should flow pretty obviously from their functions. A page to define the various tags, the aforementioned couple of pages to talk about the interactions with various campaign styles, a couple of pages about the "kinds of economies," and a page with rough advice for how to tweak the prevalence and value of items when they diverge from a given campaign's assumptions. Pad it out to 8 pages total for art, font crap, headings, etc. Hardly going to break the printing presses.
I know that if we sought deep detail on every niggly thing, the book would never be finished. But I literally threw all of the above ideas together in the span of perhaps 15 minutes--probably less. Surely, a SINGLE person, whose actual JOB is to make this kind of stuff, spending a whole day or two on the topic could EASILY produce actual rules to fit that limitation--to say nothing of a TEAM of people all thinking about it for a few days.