Is this just the value in inv_investments.AGGR_ACTUAL_COST ?
i.e. that number is the same as you would see in the Cost Plan for the investment? (and is this one of the fields populated by that "Investment Allocation" job?)
If the answer is "no" - how do I (in SQL) calculate a project's total cost from the cost plan (where it is shown correctly) ?
(I don't have access to a financially-activated instance to look at real-data or run traces for myself just now )