Conditional or Variable Min/Max Rules

Currently, in order to adjust the Min/Max values of a field, you must do so with Form Rules. It'd be great to be able to adjust these variably, feeding the value from an external source, rather than having to create a rule each time we need to adjust.

Our use case is an Equipment Ordering form. We have to set the Min/Max of the shared "cost fields" for each piece of equipment. Everything else, we are able to dynamically bring in the appropriate values, but the Nintex limitation surrouding the Min/Max rules forces us to have to hardcode each Min/Max value, making this process quite tedious to setup and maintain.