Ebay Scraper, save 4 variables to database, export .csv file.

Need a program made that will run through ebay listings pulling 4 pieces of data. Program would be run from time to time, so it would need to record where it left off, perhaps by date and time, so as not to confuse the data. Data would be stored in a database, perhaps the last 10 for each item, with an average of sales price being stored. Finished data will be exported from the database with the click of a button. Because up to the last 10 listings for the same item could be stored in the database, when the data is exported the sales price will be averaged. If 10 listings of the same item sold for $10 each, the average would be $10. If 5 times the item sold for $5, and 5 times the item sold for $10, the average would of course be $7.50. An example of exported data should resemble: 1234,123456,12345678,$7.50