Price it in tech trash. The fragments and wood are pocket change, but tech trash cannot be crafted: it comes from crates and from electronics you recycle. The unfolded calculator shows high quality metal and scrap at a Level 3 bench instead; that is its value, not a craft. And the piece has rivals. The same one builds a smart alarm or half a C4.
So ask what the phone is for. If you only need to reach other players, a mobile phone dials the same network, every player knows its recipe from the start, and it takes no tech trash at all. The fixed telephone earns its piece when the base itself needs a number: a shop by the road, a clan that calls ahead.
The blueprint is cheap research at a Level 1 bench. Craft one per base, not one per room: a phone sent to the recycler gives its tech trash back only on a lucky roll.
Questions
Telephone ×10: how many resources?
Metal Fragments ×1,000, Wood ×500, Tech Trash ×10.
