Suggestions:
Price list code is unique, hence a separate price list can be created for a single item. A distinct code can be used to maintain various prices applicable for various purposes. For example if you want to apply a different price to a dealer kind of customer and a different kind of price to a stockist kind of customer, you can maintain two different price lists. Additional price lists can be maintained for information purposes also like MRP or Retailer price. Additional routines are available in the system to create one price (Target Price List ) out of another. if they are derivable from another(Price List Parent).
In case of batch price list rate pick up by considering ref_no . If you mention the same ref_no in the price list then the system will pick up the first rate .
For example if this product FG00000308 and has price lists AIPTS and PTS which have the same ref_no as 1 , then change the ref_no 2 for max slab in pricelist .
After changing the reference number, users can check the rate that is picked up from the max slab price list in Sales order.