"In the next several months, will more flights be scheduled at various prices? In other words, should I jump on this fare? Or will something cheaper possibly come along?"
It is unlikely that there will actually be more flights on a particular route. Of course, it does happen, and then there is often a sale. This is particularly true when a carrier enters a market. For instance, not too long ago Emirates starting flying New York to Milan (a completely new route for them); this led to flights to Milan being very cheap (on all airlines) compared with flights to other Italian cities.
As for something cheaper coming along without more flights being added, as everyone said above, you never know. The rule is, when you find a fare you consider acceptable, book it IMMEDIATELY before it disappears, and then don't look back.