Is Enlightened Self-Interest Biblical?

I suspect you have not read Desiring God, Piper’s seminal book, maybe because you unjustifiably recoil at the subtitle? It fits very nicely with a pair of parables, however:

The kingdom of heaven is like treasure hidden in a field. When a man found it, he hid it again, and then in his joy went and sold all he had and bought that field.
 
Again, the kingdom of heaven is like a merchant looking for fine pearls. When he found one of great value, he went away and sold everything he had and bought it.

 
Matthew 13:44-46

 
God is desirable, and not only that, he’s the ultimate desire. If we are not seeking the gratification of having him in our lives, that makes obedience to the greatest commandment rather difficult. He is not just a set of ideas to subscribe to.