This is strictly worse than a prefilled epinephrine syringe, which a quick google search tells me costs about $10 [0].
In fact, Adamis recently tried to get FDA approval to sell prefilled syringes as an alternative to Epi-Pens, but it was rejected with demands for more expansive patient usability study and product stress testing [1].
The creator of this "3D printed Epi Injector" evidently does not understand the problem that actually needs to be solved.