Looking across multiple dates, I am seeing what you see too... my flight was a Monday afternoon flight... not sure if peak business travel dates are showing different fares. I just peeked at next Monday and am seeing tickets just shy of $600 o.w. in first on that same flight / same aircraft. Other dates are considerably cheaper. I also bought 2 days in advance, but it appears Monday fares are more expensive.

In yesterday's case, it appears people were ponying up a good chunk of change to sit up front before the 24 hour mark. Once I checked in, I grabbed the last DoD buy-up available, and the last seat either sold or went to someone who had irrops.