I don't have a good answer for this, but really like @Stacy Wright's answer. Stacy, do you also track travel expenses in this way? That's something that we currently don't even track as an event cost, and in my opinion, is a big miss in understanding the total event cost to then be able to track correct event ROI. Ideally, we would want to track travel, lodging and food all separately (I would rather have a lot of sliceable, diceable line items than one big bucket).
Hey Lori - I agree with you and know this is something we are thinking about too, but since it doesn't affect our G/L codes and budget it's not a priority ... yet! For now, we are focusing on the fixed costs we can control and ultimately answer for each month. If we did, though, I'd have to think about whether we track them in our Event Record for Meeting ABC, which would not give me a clear picture of my G/L's actual, budgeted, negotiated spend (in my opinion), or if we establish a travel "child" Event Record for each meeting that tracks travel, hotel, and food as an aggregate spend but still has line items that allow for budget categories and subcategories so you have your data segmented and by vendor if needed. Not sure if that all makes sense!
As we explore integrations with Concur, Veeva, and other software systems I think it's going to be an easier (and more automated) task so that we can really tell the story of spend in a robust way.