Automatic orders processing

I run a dropshipping business and I am looking for a software than can automatically purchase my orders. Essentially I sell products on EBay, I can download a csv file of all my orders at the end of the day, I have attached an example. I would like to be able to press a button and all of these orders get purchased on Onbuy, even better if this was done automatically as soon as I get an order on eBay. I have a stock list that has all the links to the Onbuy products (see screenshot) this list can be edited if necessary. The payment method I used to pay for these orders on Onbuy is PayPal, this never asks for a recapthca just a password. Please let me know if this is a possible task and if so a rough quote. Thank you for your time Molly