I am in general agreement with BPT and rbell. I am wary of overallegorization of the texts, which can lead to some pretty strange theologies.
As to "wasting" words: Good storytellers do not "waste" words. While the words may not have some allegorical meaning, they may advance the narrative and make the message resonate more strongly than would otherwise be the case. Jesus' parables are filled with homely images that his hearers could well imagine - many times, they may have done something similar. Maybe the woman seeking for the lost coin was familiar to those who heard the parable. It could have been someone's mother or sister, or even himself.
Now, Jesus could have simplified the story. "A person who had a bit of money lost some of it. After a search, the money was found and everyone was asked to celebrate." Ho-hum.
No, this was a woman. How did she know the money was missing? Well, it had to be counted, and there had to be some number. Maybe she was expecting the tax collector the next day, or perhaps it was for a dowry for a daughter who could not arrange a proper marriage without it. She found the coin gone and didn't just sit down and say "Well, where did I put it?" No, she fired up the lamp - oil's not cheap, you know, and you use it only when you have to - and then sets out with her broom to look into every nook and cranny. Finally she finds the coin and instead of just sliding the coin into her purse, she calls out for friends and neighbors to come celebrate with her.
The details give texture to the story and allow listeners to conjure up their own images that resonate with them. The numbers mean nothing - there is no difference between the one of 10 coins lost and the one of 100 sheep lost or the one of two sons lost. They give life to the story.
In good storytelling, there are no "wasted" words. They are the raw material from which responses of the heart are molded. They need have no great theological meaning but are designed to advance the narrative, to breathe life into teaching.