Hi Bryan,
This issue of re-baselining individual tasks for EV is one of the reasons
for not updating a baseline every time. For most of my clients, they like
the +/- 10%/20% range (most are at the 10% range). Now, where you need to
make your decisions is whether you care just about cost or about resources,
costs and durations.
For a PM to make better decisions as to when they should re-baseline, you
will want to consider creating custom fields that use graphical indicators.
We have a client that always shows a red indicator for tasks that have no
baseline. If the total reds equal more or less than 10% of the budget, the
PM knows that they should re-baseline. If still, red, the PM works with a
governing body to change their funding.
-Bill