518179 Php for auction site

I'm looking for a php developer to help be develop the back end for an auction site. Its a simple auctions site most of the functions have already been written but I'm having issues with updating the auctions when no one is logged in for automatic bidding. More then likely I will be needing to use a cron job to handle this part of the project. The idea is a bidder will put max bids that the system will bid up on a particular auction and the transactions will be saved to the DB. I have a fixed budget for this portion.