Automatic Price update via php file

Basically we are looking to get a php file made and set up on chron to run each night or each month. We have a oscommerce store and we need to get a script made where it checks our model # with the vendor to get the current list price. Each products price needs to be updated automatically into our mysql database. Our model # is same as vendor item #. Vendor frequently changes price thus we need to set up chron to check for new prices each month or every day if we have to. Please PM for vendor site and our site urls.