Through a broker, the cost is the brokers fees (commissions) plus any negotiated costs like Maint fees, transfer, closing costs. Tradtionally all fees other than broker commisions are buyers costs but they are sometimes negotiated in the deal for seller to pay. Expect to pay some where around 10% with a miniumum usually around $1500 whichever is more. I've seen the minimum as low as around $7-800 once and another at $1000.