You could do this one of two ways, both involve using
Automations.
1. Create a scheduled Automation to check the
Purchase Value field daily. For any records where it is null, change the status on related record. Might need to use the
Copy Record(s) action for this one. (A little bit more complex)
2. In the table where
status is, set the default value of
status to "Awaiting Purchase Value" (Or whatever your planned status is) and then set up an automation that triggers when
Purchase Value field is changed, and the action for the automation should change the
status to whatever you want after that happens.
Let me know if that makes sense
