yes, but Craigslist doesn't give you "your website" to organise the garage sale.
The idea is to let people create and customize the website, specifically in situations when they need to sell many things.
Also, it will be a bit of a pain if I need to update it each time something is sold.
Things I would consider adding: 1) ability to pay for the item directly on the site (you could partner with paypal on this, or offer the merchant service directly for a cost to the website user)
2) waiting list for people interested in the objects.
General issue I see with this: can you get people to pay for this when they have a free option? If you're going to offer it free, can you generate enough page views on individual sites to validate ad revenue?
Sorry... just my opinion.
I'm also in doubt whether to put more work on it or leave it as it is.