Build an Online Store

Hi freelancers. We are looking for someone to make some amends to a Magento 1.8 site for us. The majority of the work has already been completed, we just need someone to finish off what we have already built, as there is a deadline of next week and we have other projects to finish before then. The job: The site needs to be able to calculate postage costs based on distance, and prevent orders where the delivery address is further than the specified radius. We already have the base functionality built (an ajax request which is tied in to google api to calculate the distance, which then returns the custom price based on that distance and displays that to the user on the cart page where the fixed price would normally appear). It is slightly different from the way Magento normally works because the rate changes based on the distance, but this has already been done. WHAT NEEDS TO BE DONE: the custom delivery price returned needs to be added to the DB when the order is processed - a quick and easy job for someone that knows their way around Magento. The budget is very tight on this job so the chosen freelancer will be the most competitive in terms of price. We are looking to take someone on straight away so please don't delay in submitting your proposal if you have the required skillset.