Sub mangasarovdr()
Dim WB$, rR
    WB = ActiveWorkbook.Name
    Workbooks.Open FileName:="C:\PartsPrice\PartsPrice.xlsx", UpdateLinks:=0
    Windows(WB).Activate
    On Error Resume Next
        For Each rR In Selection
            rR.Offset(0, 2) = Application.WorksheetFunction.VLookup(rR, Workbooks("PartsPrice.xlsx").Sheets(1).Range("a1:b10000"), 2, 0)
        Next rR
End Sub

Sub tt()
    Dim wb0_ As Workbook, wb1_ As Workbook
    Set wb0_ = ActiveWorkbook
    Application.ScreenUpdating = 0
    Set wb1_ = Workbooks.Open("C:\PartsPrice\PartsPrice.xlsx")
    With wb1_
        With .Worksheets(1)
            nr1_ = .Cells(.Rows.Count, 1).End(3).Row - 1
            ar1_ = .Cells(2, 1).Resize(nr1_, 2).Value
        End With
        .Close
    End With
    Set slov = CreateObject("Scripting.Dictionary")
    With slov
        For i = 1 To nr1_
            .Item(ar1_(i, 1)) = ar1_(i, 2)
        Next i
        ar0_ = Selection.Resize(, 3).Value
        For i = 1 To UBound(ar0_)
            If .exists(ar0_(i, 1)) Then
                ar0_(i, 3) = .Item(ar0_(i, 1))
            Else
                ar0_(i, 3) = "=RC[3]*1.45"
                'ar0_(i, 3) = 0 ' Или так
            End If
        Next i
    End With
    Selection.Resize(, 3).Value = ar0_
    Application.ScreenUpdating = 1
End Sub