David,
It's a matter of what your peers do, according to USPAP. This is because USPAP doesn't tell you how to describe anything. Nor does it tell you how to summarize information, or how much information constitutes a summary. The URAR, for example, has certain elements of a restricted use report: In the neighborhood section, you "state" with a check mark that the market is declining, stable, or increasing (that whole check box section is a bunch of "statements.") The highest and best use block "states" the HBU, and according to the form, you only have to "explain" if you check "Other." USPAP, though, wants you to "summarize" your reasoning for your HBU determination in such a way that the user can follow it from beginning to conclusion.
For Self Contained, (if I ever had the cojones to so label a report) I would include detailed support for every statement made. How do you know the market is stable? Where'd you get the data? Show it to me. How do these data indicate a stable market? (Oh, and is this level of analysis congruent with the scope of work? Do you need a more detailed examination of the market?)
Can you imagine the volume of information you'd have to provide to support local building costs? Breakdown method depreciation? Market extraction of *each* adjustment made in the market grid? Data to support your choice of a yield cap rate? Explaining (and providing data for) why you used yield cap instead of overall cap?
So a Self-Contained Report starts at a minimum of $3,000; some won't do one for less than $5,000. And that's on a non-complex property. Someone said the difference was 50 - 100 pages. That's a little conservative, IMO.
Now, you could write a self-contained report and label it a summary without being in violation of USPAP. You could also label it restricted use, and not be in violation. But if you label it Self-Contained and happen to summarize one little thing, you're in violation.
Safest thing to do is a good, detailed scope of work: What the client wants, what he's going to do with it, and how you'll go about providing it. After you've met the requirements of the SOW, look at the report and *then* label it appropriate to the level of reporting you actually used. Personally, I'll be glad to see SOW take over next year--for the reasons illustrated above.