Airfare from BHM (AL) to LGA (NY) doubled since yesterday...buy now or wait?

I guess Delta was running a promotion yesterday because airfare from Birmingham, AL to New York City was only $171. So we had decided to buy tickets today, when we got paid. There are eight of us going in February so we wanted to get tickets well in advance. We go to buy them today and they're now almost double what they were yesterday...around $300 each. Should we go ahead and buy them for this price or do you think prices might come down some? I know they probably won't reach $171 again, but maybe $200 or so???