If you feel comfortable with that price, I would jump on it. You didn't say where you were flying out of, so it doesn't give much perspective - but in my opinion, anytime you can fly for under $100.00 one way is pretty good.
Watch what time of day you check prices. It seems like Tuesday through Thursday, the prices go down - they creep back up Thursday through Monday.
Also watch the time of day - I booked my flight at 6:00 am when I got to work; by the time I got hold of my two traveling companions and they got on at lunchtime, the price was up $20.00. Still reasonable, but I got the best deal.