Its good to get lines early but sometimes that can come back to bite you (especially when you get Sunday games lines on Tuesday)
For example lets say Bears go to a +3 between now and Sunday...we would buy 1/2 a point and have it at +3.5 and it'll be a loss for you as far as the system goes (assuming they loss by a field goal)
But for the Ravens game tomm you should bet ML anyway not buy points