Private Sub UserForm_Initialize()
For i = 1 To Worksheets.Count
ComboBox2.AddItem Worksheets(i).Name
Next i
Label3.Caption = ""
Label4.Caption = ""
Label5.Caption = ""
ComboBox1.SetFocus
End Sub

Private Sub ComboBox2_Change()
ComboBox1.Clear
ComboBox1.Text = ""
Label3.Caption = ""
Label4.Caption = ""
Label5.Caption = ""
Worksheets(ComboBox2.Text).Select
i = 3
While Cells(i, 1) <> ""
If Cells(i, 1).Value <> Cells(i + 1, 1).Value Then
ComboBox1.AddItem Cells(i, 1).Value
End If
i = i + 1
Wend
End Sub

Private Sub ComboBox1_Change()
i = 2
k = 0
While Cells(i, 1) <> ""
If ComboBox1.Text = Cells(i, 1).Value Then
n = i
k = k + Cells(i, 5)
End If
Wend
Label3.Caption = "Количество=" & k
If Cells(n, 4) = 0 Then
Label4.Caption = "Стоимость, руб.="
Label5.Caption = "Итого:" & Количество * Стоимость
End If
End Sub