Pettiness can cost much more than you may be willing to pay in interest over a lonely lifetime...
I have seen so many family situations strained over money issues. I was lucky-- my family (at least on my mom's side) was ALWAYS generous, the "give you the shirt off my back" types. That's how I grew up thinking. If I have enough and you need some, it's yours. My dad came from a very different family-- if grandma was having company, you can be sure there were just enough pieces of lunch meat and bread to make exactly one thin sandwich per person. My mom managed to affect my dad's sense of $$ to some extent, but how one is raised is deeply ingrained. The biggest moderator on all of us was losing my brother to cancer; when a thief of life like cancer pays a visit, no amount of money can stave him off and suddenly money doesn't mean much.
How many stories have you seen of a natural disaster where all the stuff is suddenly gone and all anyone cares about is finding their loved ones. I vividly recall hearing of a family victim to the earthquake in Turkey; the father was lamenting that their giant dresser fell upon his young daughter and crushed her. Suddenly, the STUFF mattered NOT AT ALL.
One of my cousins is currently battling a HORRIBLY aggressive form of melanoma. It has spread to her neck and brain. She is my age (mid-to-late 30s) and has a great husband and two adorable kids. Her parents have more money than they could ever ever need. And they freely give it to others that need it. But, no amount of money can save them from the horror of watching their daughter slip away. My cousin just reminded all of us not to wait until a terminal illness compels us to be grateful for all we have. She advises that we acknowledge our blessings and our loves NOW.
We are all capable of terrible pettiness. Even after losing my brother and then, just a year ago, losing my dad very suddenly to a heart attack one September morning, there are still times when I take people for granted. But one thing I REFUSE to EVER EVER EVER be petty about is money. A couple weeks ago, I was out with my brother-in-law, his fiance, and my other brother-in-law. The one brother-in-law, who's rather frugal, suggested stopping for a pint of beer. The other brother asked whether the suggesting brother would be paying for said pints (this second brother has admittedly fronted a number of bar bills for his brother). The brother who suggested stopping noted how he'd just bought beer for home (which he had, but still). I finally just pulled out my debit card and paid for everyone-- these folks see each other maybe once a year, and here they are bickering over $30 (Canadian!). What I'd give to buy my own brother a pint of beer...
My cheap advice: if you have kids and any kind of wealth-- small or large-- that you may be passing onto them, make a will TODAY. Set up an executor that is NOT one of your kids. Make it as equitable and simple as possible. Even if you don't have much but you have a complicated family situation or something like that, make out an explicit will with an independent executor to specify how you want things divided. Make it fair. Try to avoid leaving any family fissures after you are gone by taking the responsibility yourself now to specify how you want things handled; don't assume that surviving spouses or parents or kids will be fair if left in charge of your affairs.
And, if you're quibbling with a family member, friend, or other person who means anything to you over something petty like money or stuff, swallow your pride and call them up and make things right. Even if it was "their fault," call them anyway b/c it was probably at least half your fault. I didn't talk to my parents for nearly six years. I could've made it seven, but I finally called and made things right. My dad died suddenly one morning just a year-and-a-half after I made that call. Don't wait for that unexpected call-- it will come one of these days when you least expect it. People's fleshy, animated spirits vanish in a flash, and their absence is so final and profound. Please, love the ones you're with NOW.