shop for something second hand.
In my city, the police take unclaimed stolen bikes to the auction about once a month. I've picked up a few real good deals there. I've also seen people who don't know what they are buying pay way too much.
I had to watch for 3 or 4 months to get the last two bikes but it was worth the wait to get bikes for $150 that retail for $600 - $700
I think it will be hard to find a step through frame since the resurgence in popularity only happened in the last 3 to 5 years.
Try craig's list.