How should I buy a domain name?

I am trying to buy a domain name from someone that owns it. I currently own a couple domains through go daddy and they say that they will contact the the person that owns the domain and try to get them to sell it for seventy dollars (even if the domain isn't offered for sale or bought, they keep the seventy bucks), They also charge a 10 percent commission on the domain sale (which doesn't give them much incentive to get me the lowest price). I know all of the personal information of the person that owns the domain through a www.whois.net search so coudn't I just contact them directly and cut out the middle man?