Good luck with it. I think the consensus on here is we all like to see a Z3 saved if possible 
But speaking from experience I’ve saved cars I probably shouldn’t have done for economic reasons. And that includes my engine swap project. Although the engine cost was the least of my worries with that one as it effectively came for free from a write-off I did break. It’s usually the completely b*ll*xed suspension and brakes that are guaranteed to run the cost up as secondhand parts here rarely cut it.
But speaking from experience I’ve saved cars I probably shouldn’t have done for economic reasons. And that includes my engine swap project. Although the engine cost was the least of my worries with that one as it effectively came for free from a write-off I did break. It’s usually the completely b*ll*xed suspension and brakes that are guaranteed to run the cost up as secondhand parts here rarely cut it.