"Sorry, bad analogy. The intent is different. Whether spending $500 or $50,000, the intent is the same, only the amount varies."
No, it's a good analogy, because the difference in what can be accomplished with a given sum can give rise to a difference in kind.
"Reason tells me that for a person of a net worth of $100,000, and with $10 million, an expenditure of $50,000 is the same percentage of personal wealth."
And reason tells me that the percentage of wealth is not the decisive factor. The money has absolute value in terms of purchasing power, and that is the decisive factor.
"I see nothing inherently wrong with spending your money the way you wish."
It's not a question of an inherent wrong in spending your money the way you wish. It is a question of a wrong arising as a result of spending a given sum in a given way.