Post a small sample workbook, and make sure to show the desired results
Use [Go Advanced] in lower right, and then the paperclip icon
Meantime, here's a guessed-at approach and sample workbook
Option Explicit
Sub AddPrice()
Dim wsPrice As Worksheet, wsInvoice As Worksheet
Dim iInvoice As Long, iLastInvoice As Long
Dim iPrice As Long
Application.ScreenUpdating = False
Set wsPrice = Worksheets("Price")
Set wsInvoice = Worksheets("Invoice")
iLastInvoice = wsInvoice.Cells(wsInvoice.Rows.Count, 1).End(xlUp).Row
For iInvoice = 2 To iLastInvoice
iPrice = 0
On Error Resume Next ' in case not found
iPrice = Application.WorksheetFunction.Match(wsInvoice.Cells(iInvoice, 1).Value, wsPrice.Columns(1), 0)
On Error GoTo 0
wsInvoice.Cells(iInvoice, 7).Value = wsPrice.Cells(iPrice, 7).Value
Next iInvoice
Application.ScreenUpdating = True
End Sub