Interesting thread. Actually a little shocking.
I don't know for sure because I'm mostly spending company money and don't actually see the bill - also, I only occasionally see the fares booked (and sometimes when I do see the fares I don't even really notice unless its unusually cheap or really expensive) because someone else does it for me in many instances.
Best guess based on my 2012 segments and my average fares is between $45K-$55K
I'm absolutely floored by all the EXPs on here that spent under $5K. Wow. Well done. It also makes me wonder if there is an undisclosed $ level that gets people to EXP (or plat or gold) as several people I work with have been granted EXP even though they didn't hit the posted qualifications, but spend more than some other EXPs that qualified on the posted qualification terms.