When I was a college student I priced Walmart and the dollar store on over one hundred items. My experience was that the dollar store was indeed cheaper than other sources.

I did notice that some of the products (like deodorant) typically "the sell by" date was much faster, but that wasn't a deterrent to me at the time.

I bought from the Dollar Store exclusively for 3 years for two reasons : 1) It was cheaper 2) the closest competitive store was 20 miles away