Sorry for the lack of response, here. As whpalmer4 noted, Help -> Send Feedback is generally a better venue when you're looking for any kind of response from us. The forums are more user community driven, in general, though we try to chime in regularly.
Reporting remains an area we'd like to work on strengthening, but based on customer feedback it appears to be a lower priority for most of our users than you might imagine. That's compounded by the fact that it's seemingly impossible to write one report that satisfies the requirements of two users.
That's not meant to imply that we won't be adding any reporting. Rather, we need to be selective about exactly what reports we do include, so the more better we understand our users' requirements, the better we can generalize them into reports that are useful to the most users.
In the mean time, over in an OmniPlan -> Extras thread
http://forums.omnigroup.com/showthread.php?t=19933 forum user mattao has written a cost tracking AppleScript. This calculates the cost of your project plan up to a fixed point in time. I realize that's not what you've asked for, but I wonder if it could form the basis for a new script. If you have the wherewithal, you could start a new OmniPlan -> Extras thread and spearhead a collaborative effort to get just the values you need.