Okay, let us summarize. This started with a user saying, paraphrased:
"Even if my item list 48k in value, it would still have been a wise investment for me, because of the money saved from using superior tools has saved me more than that'
To which you replied, paraphrased:
"Oh come on, an item losing 48k in value can't be a good investment"
This despite said player providing insight as to why he would see it as a good investment,.
After this you have continued to argue your point, despite several people who have even provided numbers of why superior tools are saving or making them more money than putting an equal amount of money into passive income alternatives.
So back on topic somewhat:
Item value depreciation in this game is only ever an issue if you are making the purchase for the wrong reasons in the first place. If you know what an item does for you, you´ll know what it is worth to you, and you wouldn´t need to worry about the item losing value.
For sure. an item not losing value after purchase would be great, and item increasing in value would be ideal. It might feel bad to see the value of your item going down, but if your cost savings offset the price drop (which it will do. eventually) it is a non-issue. Also, there´s just the option of keeping the item if you don´t want to sell it at a loss