Попробуйте:
Sub Evaluation()
Dim LastRow As Long
Dim i As Long
Dim Result As Integer
LastRow = Sheet1.Range("A" & Rows.Count).End(xlUp).Row
For i = 2 To LastRow
If Sheet1.Range("A" & i).Value <> "" Then
If (InStr(Sheet1.Range("A" & i).Value, "(") > 0) And (InStr(Sheet1.Range("A" & i).Value, ")") > 0) Then
If (InStr(Sheet1.Range("A" & i).Value, "pck") > 0) Or (InStr(Sheet1.Range("A" & i).Value, "pcs") > 0) Or (InStr(Sheet1.Range("A" & i).Value, "pack") > 0) Or (InStr(Sheet1.Range("A" & i).Value, "pots") > 0) Then
Sheet1.Range("A" & i).Offset(0, 3).Value = Sheet1.Range("A" & i).Offset(0, 2).Value
End If
ElseIf Sheet1.Range("A" & i).Offset(0, 1).Value > 0 Then
Sheet1.Range("A" & i).Offset(0, 3).Value = Sheet1.Range("A" & i).Offset(0, 2).Value * Sheet1.Range("A" & i).Offset(0, 1).Value
ElseIf Sheet1.Range("A" & i).Offset(0, 1).Value = 0 Then
Sheet1.Range("A" & i).Offset(0, 3).Value = Sheet1.Range("A" & i).Offset(0, 2).Value
End If
End If
Next i
End Sub