Rich Keyword Domains Vs Poor Keyword Typins.....which are better for ppc?

[WebsiteTraders.Com]

when buying a domain for PPC monitorization i come accross rich keyword domains but have no traffic.........should i buy them and optimise in parking.......or should i focus on typin with low paying keywords? typin with rich keyword is ideal but thats difficult n not always possible with limited budget.......so which ones should i pick?