Based on prior knowledge, the number of doors can potentially impact the decision to buy a car. Here is the analysis of the relationship between the feature "doors" and the target variable "decision to buy this car":

- Unacceptable: It is expected that cars with only 2 doors or 3 doors might be rated as unacceptable more often. 
- Acceptable: Cars with 4 doors and 5 or more doors are commonly considered acceptable by buyers. 
- Good: The number of doors might not have a significant impact on the decision if the car is otherwise good. Hence, all categories of doors could be included as having a "good" rating. 
- Very Good: It is hypothesized that cars with more doors, such as 4 doors or 5 or more doors, could be rated as "very good" more frequently.

Based on this analysis, here is the dictionary:

```json
{
	"unacceptable": ["2", "3"],
	"acceptable": ["4", "5more"],
	"very good": ["4", "5more"],
	"good": ["2", "3", "4", "5more"]
}
```