There are any number of perfectly serviceable rifle actions which would be made for about $100, including products from the US, Japan and Europe.

In terms of Mauser 98 actions, the originals were made of a very ordinary grade of low carbon steel, about like 1030, and subjected to pack carburising, with process controls which would be considered very basic nowadays. It was optimised for this, with the strength based on design (and building in a large factor of safety).