Merge Query against a range

I have made 2 queries - One based on list approach and one based on Table.SelectRows approach. 

This is a mini-mockup which you can fit in your code.

These will definitely improve performance. Let me know whether the improvement is acceptable or not/

The Excel mockup is uploaded to https://1drv.ms/x/s!Akd5y6ruJhvhuT0ZjSMjlq22TTQZ?e=AkZ7gr 

let
    Source = Excel.CurrentWorkbook(){[Name="Sales"]}[Content],
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Product SKU", Int64.Type}, {"SalesDate", type date}}),
    StartDateList = List.Buffer(ProductCostLookup[Start Date]),
    EndDateList = List.Buffer(ProductCostLookup[End Date]),
    CostList = List.Buffer(ProductCostLookup[Cost]),
    SKUList = List.Buffer(ProductCostLookup[Product SKU]),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "Cost", each CostList{List.PositionOf(List.Transform(List.Positions(StartDateList),(i)=>[SalesDate]>=StartDateList{i} and [SalesDate]<=EndDateList{i} and [Product SKU]=SKUList{i}),true)})
in
    #"Added Custom"

Table.SelectRows approach

let
    Source = Excel.CurrentWorkbook(){[Name="Sales"]}[Content],
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Product SKU", Int64.Type}, {"SalesDate", type date}}),
    BufferedTable = Table.Buffer(ProductCostLookup),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "Cost", each Table.SelectRows(BufferedTable, (x)=> x[Start Date]<=[SalesDate] and x[End Date]>=[SalesDate] and x[Product SKU]=[Product SKU]){0}[Cost])
in
    #"Added Custom"