A couple comments about things mentioned in this thread.
First, a statement like "each half point is worth about 10 cents..." is at best misleading and at worst flat-out wrong. A book typically charges 10 cents to buy a half point. That is the ONLY association between a half point and 10 cents. How much a half point is worth depends on the particular pointspread. Obviously, the bigger the pointspread, the less a half point is typically worth. For example, would anyone equate buying on or off 25 as being the same as buying on or off 2 in college basketball? Not even close.
I checked my database for this season's college basketball. I show a closing line of -11.5/-12/-12.5 occurring 153 times. Of these 153 instances, the favorite won by exactly 12 only twice for 1.3% of the time. 153 is not a big sample size, but I suspect the result will not deviate by much for sufficient sample sizes.
Second, NEVER buy a half point for 10 cents. You are wasting money. The books already have a nice edge. Why help them out even more? Sure, every so often that half point saves you. But, in the long run, not nearly frequently enough to justify the cost. Ask yourself this: if a half point is worth 10 cents (or more), would a book offer it to you for 10 cents? Of course not.
To the person who buys a point for every game at a price of -130: your break-even percentage is 56.52%. Break-even for -110 is 52.38%. Break-even for -120 is 54.55%. I know I won't change your mind. But something to think about...