Teaching kids to value things

Once again I am blogging an hour and a half before shabbos, but we are all showered and dressed so I snagged a few minutes.
Almost a year ago, I was standing at a busstop, when my phone beeped. Like a good pavlovian dog, I of course started rummaging through my bag to find it. While picking it up, it slipped out of my hand and fell to the ground. I picked it up and, thankfully, it was still working. There was an older man in dissheveled clothing at the busstop who had seen this all happen. He gave me a stern look and warned me to be careful with my phone. I said it was fine and that it was just an accident. He then said, "If you knew you could not replace it, you would be much more careful with it." Meaning if you really valued your phone and did not have the money to pay for a new one, you would not be so careless. This harmless incident has stuck with me for a long time. I mean, who takes advice from random, possibly crazy strangers standing at New York City busstops, but something about this resonated with me.
I find myself thinking about this idea a lot recently, when dealing with my kids. I am always toeing the line between letting them roam free because kids are kids and cannot walk on eggshells and the feeling that I need to teach them that some things are off limits.
While I do hope my children are not excessively wild, we do deal a lot with ripped books, colored on walls and sofas, scratched CDs and most of all, broken DVD-players.
We do not have a TV in our home but we do allow our children to watch videos on a portable DVD player (full disclosure- they are watching right now so I can type in peace).
Most of the time whent they are watching, I am nor supervising them so closely. I am usually making dinner, on the phone or doing something else. And often I return to find that some damage has been done to the player or the DVDs. They are rough with it and pull off the cover, they drop it, they touch the inner parts that are not meant to be touched...and so the players break. And I tell them I will not replace it because they broke it and need to learn consequences, but then I always do. By now, I have gotten smart and I buy a warantee with the players. When it inevitably breaks, I go back to the store and get a new one for free, paying 15 dollars for the new warantee.
But I worry that my children are not learning that things have value. That money doesn't grow on trees and that not everything is replaceable. I can tell them over and over not to rip a book because then it will be ruined but usually it does not stop them. My pleas to color only on paper are only sometimes successful. Y has a "mural" by his bed now that is his dedicated place for coloring..which has not stopped him from drawing on his legs with markers twice this week.
So I am torn between being an overly permissive mommy who lets her "kids be kids" and being a police woman, constantly saying "no" and confiscating all the markers and crayons in the house. As usual, the answer lies somewhere in the middle, in finding the magic balance. Until I do, I will continue to ponder how to teach my kids that things do not just magically replace themselves. Suggestions welcome.
Have a wonderful shabbos!