Depending on how often my DS has been up nursing during the night (and, consequently, how full I am in the morning), I can often pump enough for 1 bottle plus a bit more towards a second (1 or 2 oz). If I delay my pumping session until later in the day, I can usually get about 1 1/2 bottles from a single session.
Am I remembering right that you're using an Ameda PY or Lansinoh double electric? I had been using the PY, and it was crapping out on me, so I've been renting a Symphony pump. I LOVE the Symphony. I'm getting much better output and I find it to be so comfortable, plus it's very quiet when I'm on conference calls Anyway, it really might be worth renting a pump to see if you get better output.