Try:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim W As IO.StreamWriter
Dim i As Integer
W = New IO.StreamWriter("F:\TEMP\Daily Purchases" & ".txt")
For i = 0 To ListView1.Items.Count - 1
W.WriteLine(ListView1.Items.Item(i).Text + ":" + ListView1.Items.Item(i).SubItems(1).Text)
Next
W.Close()
End Sub
and you will have
Apple:5
Banana:3
in your file.