Is there such a thing as an Online Dollar Store?

Technically there is only one exclusively Online Dollar Store which is Dollar Fanatic LLC's 11 for $10 website at https://www.11for10.com an exclusively Online Dollar Store that sells everything for $1.00 each, with free shipping when you order $50 or more.

All of the $1.00 items for sale qualify for the Buy 10 items at $1.00 each, get the 11th item Free automatically (You must add at least 11 items to your shopping cart for the 11 for $10 Sale to work). 11 for $10 does have some limits on products so you can’t just buy everything in the quantity you want which can be a little irritating at times

Of course, there are a couple major players in the Dollar Store Industry that focus primarily Offline, however they do have Online options and don't sell everything for $1.00 each.