that site is neat. Would've never guessed there are so many options for a flashlight, of all things. I'm curious how these sites manage to keep the pricing up-to-date.
Those are just the major brands. There's a lot more only available from mildly sketchy Chinese sites, most of it bad but some of it excellent. There are exotic customs that cost hundreds and sometimes even thousands of dollars. There's a significant hobbyist/DIY community as well, even open-source driver designs and firmwares.
I guess this is a model that can be applied to a lot of products/services - even for things like Job Search, apartment search etc, as long as the data is reliable and is in machine readable format. I forget the name of the site - few years ago, Google bought a site that helped people look for laptops, but instead of saying 8GB RAM, it said "run photoshop fast" or something like that.
The pricing is the easiest part. As an affiliate you get access to an API that lets you query it. Of course it is heavily rate limited and sometimes fails outright. Accessing certain parts of the API comes with strings attached too. All of the non-amazon prices I refresh by hand every few months.