So, if you buy a piece of gear for $1,000 and sell it for $1,500 you have a $500 profit. Depending on your tax bracket you would owe between zero and $185 (37%) in income tax. You might owe some state income tax as well depending on where you live. Would anyone here find this offensive? Paying around $200 in income tax because a statistical outlier of a piece of gear appreciated?
This is a nothing cheeseburger...its not a big deal to pay income tax as a hobbyist if you get lucky and something appreciates. If its a big deal, start a business, pay the fees necessary and set up shop. It looks easy and is hard as heck to make money in the audio business.
OR
You can pay a few dollars in income tax on the absolutely rare occurrence that a couple of items here or there MIGHT have appreciated enough to generate a profit. Senseless handwringing.