When your business is buying and reselling specialty obsolete inventory, you may very well end up sittting on it for years or even decades (if your around that long) before a buyer comes along to purchase it. That part you paid $30 for from the seller, may have only cost them $7 but when its sitting on the shelf for 20-30 years its costing them money as well... Idle inventory is a tricky area of business to be in... I dont like it one bit either but guess what.... it is what it is.
Dont like it then do something about it.
I tried and will probably lose several hundred dollars as a result....