@jetter …”A person who has invested $150K in his system will have a resale value of about $75K after 5 years. Cost of ownership $15K per year.”
Well, for me, I would do the math a bit different. So, my system is about $150K. Typically I will go for 10 years between major upgrades and I trade old equipment in. The roots stretch back fifty years. My last upgrade would have been $75K, but I traded stuff in… so out of the pocket was only $50K. But most current investment would still have residual value. Say half. So $25K of depreciation.
So, $2.5K / year. I listen three hours a day. That is $2.50 / hour. But there is no need to upgrade… so I could continue to drive the cost down.
One amp I kept for nearly 18 years. It was new and listed for $10k I traded it in and lost only $500.
So, nothing wrong with your calculations, but it really depends on how you invest and length of time.