Just edited my earlier post to mention that my "about $700" was actually only the 'OldSpend' part (and thus inaccurate), as mine isn't even showing the 'TotalSpend' right now.
A quick search suggests that 'TotalSpend' disappears for a little while if you bought something recently (which I did, a couple of DLCs), so it can take time to recalculate the total.