I found a diesel heater once new in an open box, there was a tag that the customer returned it because it wouldn't ignite, threw an ignitor in and worked like a charm, over a year later and my dad is still using it in his shop

Also found a window unit AC, still in wrapped plastic, I believe it was returned and thrown out because it didn't come with the remote, again over a year and my dad is still using that in his shop, you just have to walk up to it to turn it on and off lol