The buyer and the seller are responsible for the payment of their own respective legal fees. If the buyer is getting a new mortgage he is responsible for payment of legal fees for the preparation and registration of the mortgage documents. While the mortgage lender reserves the right to appoint its own lawyer to prepare and register the mortgage documents, it will generally, upon request, allow the buyer's lawyer to do so.
You are responsible for payment of costs incurred by the lawyer on your behalf for title searches, tax searches and registration charges.
You should discuss legal fees when you first contact your lawyer. He will be able to review the various aspects of the transaction and provide you with a close estimate of the legal fees, GST and other costs which you may incur.