need an API developer for ecommerce application

need api develped for 2 things: 1) an api between shipstation & gunbroker.com to pull orders from gunbroker to shipstation and also to send shipping notice back from shipstation to gunbroker. 2) an api to pull data from an excel file to update gunbroker listings to be able to change things such as price, quantity available on live gunbroker listings and to cancel listings. I have current shipstation account and I have gunbroker account and I have a Gunbroker sanbox REST devkey. I would like to know the ballpark cost to set this up and also the timeframe of when I could have it. thanks