Hi sune
This is possible, for sure, but it would need custom development if you want this to be done automatically and custom coding is out of the scope of our support service.
Another approach (maybe), would be by using our ATUM Export PRO, you can export any data (if that other purchase price you have is stored as a regular meta key) and then, import the data back to the ATUM's purchase price column.
Best Regards,
Salva.