<snipped everybody, because R66 and I-40does not quite apply as a
proper metaphor here, just a loose one>
Okay, rather than applying this to the OTU, let's build the basic
economic model from the ground up.
Positing one change to the jump drive: Jump Exit can take place within
up to 100D of an object with natural gravity (assuming, effectively,
the gravity tides model, and there is a penalty for the further away
from the 100D limit that you aim to jump to), but Jump Entry requires
being at or beyond the 1000D limit.
(possible: multiply the maximum effectiveness distance of all grav
drives? I never ran with M-Drives dropping their efficiency)
(particular economic weirdness of YTU can wait)
Given this model of in-system movement, with no changes to
jump-movement, what are the most dominant transportation and
system-exploitation models going to look like?

Bonus Round! Create some variant of the games presumed economics and
figure out what the effects of that would be, especially in this
model. Such as cheap spacecraft (everything space worthy costs 25% of
book) and expensive starships (except jump drives, which are at 150%
of book).