Automatic price updates for Zencart

My Website is [login to view URL] I need the prices to update with the current fluxuations in Gold Silver Platinum and Paladium through out the day. The updates should be automatic and I would like them to update as quickly as possible with the time not being over 10 minutes. 20 seconds would be nice. My website is hosted by godaddy and I have purchased the upgraded package so I can run scripts and allows for cronjobs. Thanks Scott Scott McMicheal Silver City LLC [The Administrator removed this message for containing contact details which breaches our Terms and Conditions.]