If you are handy and have some tools like needle files, a vise, cold blue, etc, the grips screws can be repaired....unless really screwed up!!! I have repaired and reblued many grips screws to like new condition.
$50 for 2 grip screws seems excessive to me. Have you contacted Tom Heller(Luger Doc) on this forum?? He has a large number of new parts for the Mauser Parabellums. I have delt with him many times and you can be comfortable dealing with him.
I own a number of 1911s and shoot them all. That are also beautiful weapons to me, especially the WWl and WWll ones. Now the tupperware handguns, that is a different situation all together....