Bought two one way tickets for $103.98 each on April 7th. Got reimbursed on April 11th - one for $103.98 and the other for $96.02.

My strategy was to book tickets for someplace I actually wanted to go - in my case, Las Vegas. I didn't find fares that were close to $100 on the dates I wanted to travel, but found these tickets for $103.98 each way a few days earlier and later for my departure and return. So, I booked the tickets for the destination I wanted, but on dates that were at the right price. After I was reimbursed, I went back and changed the flights to the dates I wanted and paid the difference with travel funds.