I think it's part of a larger struggle that all Christians have about the concept of ownership and spending on personal luxuries vs. self-sacrificial giving to others. We can always ask ourselves that about anything, not just pins: do I really need that book, or that pin, or that trip to Disneyland, or whatever.
At first, it took a lot of coaxing to get me to take a trip to Disneyland at all, because I felt guilty about spending so much money on own pleasures. Now I'm better with it, but every now and then it twinges at me. As my income has grown, my charitable giving has as well, so while I can't say I'm giving self-sacrificially I don't feel as bad about spending a bit on a pin knowing that I am also spending quite a bit more on helping others. Am I buying off my conscience? I can't say for sure. However, if you go down the rabbit hole of "am I doing enough?" you won't get out easily because the answer is "no." We can never do "enough," which is why we must rely on God's grace. Martin Luther once said that the phrase "am I doing enough?" was Satan whispering in your ear that you can (and must) save yourself by your own efforts without relying on God.
What I do think, from a theological perspective, is that the issue isn't necessarily about any absolute amount of money one is or is not spending on others. Rather, it's the extent to which something that is not God acts as a god in your life. When Jesus told that wealthy young man to sell all his belongings, it was because no matter how good of a person he was, that was something he could not do. His wealth acted as a god in his life. Of course we are supposed to give to serve and help others, but Jesus didn't have that same conversation (that we know of) with every rich person He knew. He did, however, have that conversation about what your gods are to everyone in one way or another. So I guess the question is, are your pins your gods? Do you, in a meaningful sense, worship them? Do they take up a place in your life that ought to be taken by God?
I'm lucky, in a sense, that we had a massive flood in my city last summer and I was evacuated for a week. While none of my stuff was actually in danger of being lost (by virtue of living on a second floor of an apartment building) it still gave me the opportunity to do some good values assessment. It turns out that while losing my pins or my awesome DVD collection or whatever else would really suck, it's still just stuff. I could lose it and life would go on. If Jesus asked me to sell it, I could do that (which then raises the question of "well why don't you then?" which brings us back into that vicious circle I talked about already).
) Just my two cents.
