Based on prior knowledge, we can assume that the price of maintenance (maint) feature may have some influence on the decision to buy a car. Let's analyze the relationship between the maint feature and the target variable (rating of the decision to buy the car) in order to create the dictionary.

Here is the analysis:

- Unacceptable: The maint feature value is expected to be very high, indicating that the maintenance cost is too expensive to consider buying the car.
- Acceptable: The maint feature value can be high or medium, meaning that the maintenance cost is manageable and does not negatively impact the decision to buy the car.
- Good: The maint feature value can be low or medium, implying that the maintenance cost is affordable and positively influences the decision to buy the car.
- Very Good: The maint feature value is expected to be low, indicating that the maintenance cost is very low and highly influences the decision to buy the car positively.

Based on this analysis, we can create the following dictionary:

```json
{
	"unacceptable": ["very high"],
	"acceptable": ["high", "medium"],
	"very good": ["low"],
	"good": ["low", "medium"]
}
```

Please note that the dictionary includes only the maint feature values that are highly likely to be associated with each target class.