Generally it is advisable for the Seller to use an escrow service. Such escrow service may be already provided by your registrar or you can hire one on your own.
A reputable escrow service is indeed necessary, such as escrow.com
Escrow services will charge you a fee and/or a percentage commission on the sale amount. A minimum fee (such as $50) may be required.
It is between the Seller and the Buyer to agree who pays the escrow fees.
