The shooting board may be a bit over priced in our opinion, but there isn't much competition commercially. Many people may enjoy making them, but I dont know of a single source that sells them ready made in the UK. There are one or two in the USA, for example
https://ticovogt.com/toolworks/index.php? main_page=product_info&cPath=1&products_id=7&zenid=6ce4e1fbd20ee8f0c080ad6344c239b9 . I am surprised that there is nobody making an offering using some nice timber and workmanship, even if it is a working tool. I imagine that a large percentage of the forum members who use one will have made it themselves, but how often does somebody join the forum and say "i have got a mitre saw but my picture frames are wonky. How can i make them better?" They are told to go and buy an old stanley, refurbish and tune it, make a shooting board etc. Being able to buy a board, i imagine would be an attractive proposition.
As for the headphone stand, it is not going to be sold to a woodworker, but if joe public decided that they want it, £50 will purchase it. If they decide to try and make it themselves, then they probably wont save any money having bought the timber, some tools, finish, time etc. It is only woodworkers who generate spare bits of wood after other projects- other people have to buy them.
Fair play to him if he can sell a few things made from his offcuts. I've said it before, lets not reduce the value of projects to a small markup on the cost of materials, instead the price should be what the market will bear.
