2nd Project of the Web Development Specialization Course from Harvard, Commerce. The poor man's Ebay.
Made on top of Django. I am sorry if the code seems spaghetti, but try reading it once, it won't be that tough. I hope this helps for references if you are stuck somewhere :)
In case you are interested in the problem and think you can solve it in a better manner (which is very much possible), check it out here: https://cs50.harvard.edu/web/2020/projects/2/commerce/
Here's a preview: https://youtu.be/Um-fgIChNoc