How do you aquire a parked domain name?

Dear Internet, how do you acquire a parked domain name?

I'm about to launch my start-up company which will sell software services. I'm deciding on an appropriate domain name to use, but all relevant names have already been taken by domain parked sites filled with ads. It is quite frustrating to see good names being wasted on worthless ad spamming pages. I don't mind paying for a com domain, but the prices these domain parkers ask are steep; 500 to several thousand dollars for uncommon names. Especially since they themselves pay at most 8-15$/year to keep the domain parked. So how should I go about aquiring a domain name? Should I use a broker such as Sedo or try and contact the domain owner directly? How do I ensure that I wont get ripped off?