First, I'm using these two definitions from dictionary.com:
1. Rashly or wastefully extravagant
2. Giving or given in abundance; lavish or profuse

The son certainly was wasteful with his inheritance, but if I look at what must be considered wasteful extravagance, abundance, lavishness, I see the Father's love for his empty shell of a son.

I read (I think in Scot McKnight's book but I don't have it handy) that the standard ritual for the village elders to enact when one of its members' children broke from the family and left the country and then returned, was to spot the returning child before he entered the city, gather the elders, break a pot at the child's feet as a representation of the child's banishment from the village.

Does the father's countercultural reaction cost him social standing in the village? In any case, the Father, having spent his time looking our for his son's return, was being wasteful with that resource as well.

Then there's the party. It's interesting how every one of these stories in Luke 15 ends with a party (and Jesus directly interprets each parable to remind his hearers about heaven's rejoicing at the return of a lost person).

I love how Jesus tells a story of extravagant, abundant love in response to his enemies' chalenge to him not to identify himself with sinners.

Does that help a bit?

In this case, the concept of letting the son go to fall on his face in hopes he will repent seems the best idea. You can still lavish love on them when their in jail or out of arms reach or no longer married to you.