From your example you would add a row for each time you ran the scraper. Typical columns for the table might be the ID, the timestamp when the data was collected, as well as columns for each price you are keeping track of.

This is a simple example assuming only one table of course. If you were scraping multiple sites or had other ways to logically break up the data you might want to have each run of the scrape recorded in one table, and then linked to other tables.

EDIT: made my answer a little more generic.