Categorizing prices based on a dynamic report filter

Hello Anyone, 

Im struggeling for a few days with this problem for which im unable to find the right solution. 

I've created a small test  dataset with the follow coloms of data: 

Unieke sales number - Integer

Date - Date/Time 

Week# - Integer

Month# - Integer

Day# - Integer

Invoice# - Integer

Employee# - Integer

Product# - Integer 

Productdescription - String 

Price - Decimal Number 

*For this test dataset i used 2 products (product 1 and product 2)

The goal is: 

To create a dashboard where the user can determine the range of the mode price. Where the percentage of deviation ( allowed by the user) will determine the categorie where the price will be allocated. 

Category's are: 

- Low price  ( price is lower than modeprice - allowed deviation)

- Price within Range  (price is within the range mode price +/- devation)

- High Price  ( price is higher than price + devation)

My approach:

1.  First i want to determine the mode price per product. This price will be my standard price ( i fixed this :D) 

2.  I want to give the user of my dashboard the ability to determine what percentage of deviation they want to allow ( what if parameter, fixed this too :D)

3. Last but not least the problem: I want my prices ( on transaction level) to be categorized based on the devation determined by the user of my dashboard.  

I Hope someone can help me or point me in the right direction 

Thanks in advance