I think that is pretty reasonable considering sedo also handles the tranfer and contracts,has anyone used them for this
taken from sedo terms
If you are a domain buyer or seller, you can secure your domain transfers using Sedo's Domain Escrow service even if the transaction was not conducted through Sedo. Domain Escrow fees for an outside domain sale are 3% of the sales price (for minimum commissions please see price list). This amount includes the cost of receiving your funds via international wire transfer as well as processing of the credit card payment. The only additional fees are those charged by your registrar and bank.
taken from sedo terms
If you are a domain buyer or seller, you can secure your domain transfers using Sedo's Domain Escrow service even if the transaction was not conducted through Sedo. Domain Escrow fees for an outside domain sale are 3% of the sales price (for minimum commissions please see price list). This amount includes the cost of receiving your funds via international wire transfer as well as processing of the credit card payment. The only additional fees are those charged by your registrar and bank.