eBay- if you decide to go with Intel: dell latitude 7470
As of 2019, up to date laptop with stellar performance and extra clean chassis, would be the dell latitude 7480, excellent battery life.
Old laptop models with a lot of modular component modifications, T420s or T430s.
i5m-gen2 / i5m-gen3 with up to 16GB RAM and 3 levels of SSD options, 2.5 x2, and mSata.
Optimized for wXP - w10 OS generations, and Linux.
Terrible battery life though.
Agreed with other post, A9 is horrendous in performance.
Ryz-3 could get you decent performance on SSD, but Ryz5 is probably where competition is at.
AMD Ryzen 3 3200U Processor 2.6GHz; 8GB DDR4-2400 RAM; 256GB Solid State Drive; AMD Radeon Vega 3 Graphics
In-store Micro Center price: $350
The term, 'cheap' may imply really entry level parts and low quality, or unacceptable performance.
How about the term, inexpensive, low-cost or discount?
In terms of video performance/streaming, 1080p videos streaming from websites? On Chromebooks, they're smoother on a good and up to date, dual/quad core.
On Windows 10? It's a resource hog, Ryz5 or i5-gen is recommended, but Ryz3 or i3 would suffice with 4GB RAM.
Would it need to do 4K?
Seen a Win10 AMD-A6 with HDD do the job on a laptop, but after a few months, the performance was not great.
I'd stick with Intel for what you could be purchasing for a few hundred dollars.