I think you always have to with best available/value especially early in the draft. For instance, in a Yahoo Pub league, I drafted Ensberg and Chipper back to back even though there is only one 3B slot available. Everyone knows that I have two very good 3B and I will probably end up trading one of them for something I need.
"Think of how stupid the average person is, and realize half of them are stupider than that." ~George Carlin