Some of us have millions of dollars in the bank. As a friend recently said, "now that we're dealing with 'play money' what about doing this or that". At some point the number of zeroes loses relevance when considering expenditures.
Now the question comes to mind as you get into these regions of money and spending, "do I 'owe' it to others in any way to share my wealth." Does spending on oneself ever reach an immoral level? I'm not certain how to answer that. I'm sure that many people in the world think that my 2300 square foot apartment and $16k two-channel system seems extravagantly sinful spending. How can I question someone that lives two blocks away in a $4 million house with a $100,000+ stereo???
I think there are no absolutes in this question. Your context and frame of reference enter into the evaluation and you can't say with absolute authority that spending $100k on a speaker system is immoral any more than me spending $3500 for speakers in a $16,000 system.
I feel no guilt, but I do wonder if there's a point where I should. By the way, I DO share my wealth to a fairly high degree, beyond just what I owe in taxes.
Dave