Dynamic Min/Max Values

There should really be a way to set the Min/Max Values of a field dynamically. Right now, you have to hardcode the min/max value based on conditional logic, but it would be absolutely amazing to provide the min/max fields a dynamic variable.

For Example, if someone makes a selection, then to programmatically have the min/max values of a related field be adjusted appropriately, rather than having to have a rule for every possible selection...