Welcome Sigme,
Depends on what it is worth to you since that gun has carbon fiber grips and they are not made anymore. If the GF grips are not important contact Tom Watson (theirishguard) on the forum and see what he can get you a new R9 for. Many of us has gotten guns from Tom - great dealer and guy.
As far as early model. A 525 is not that early. In fact the guns before 450 were about trouble free. Mine is only a few numbers from 525 and has been fine. Then again the first cracked slide ever was 530 - then again I heard of some cracked slides in the 1300 to 1500s also. So don't concern yourself with it . There were only a few cracked slides and the company will take care of it if needed.
As far as the price - don't know what to tell you. I have a NIB as my second R9 in the 900s and if I decide to sell it I'll ask around $900 so it would see fast - but that is just me.
Don't know if I helped you.