Lon Seidman just reviewed a $180 HP laptop from Walmart. Intel N150 processor, can run Linux and has upgradable RAM and storage:

https://youtu.be/FRNz-xakWB8

But then, 2 min into the video they upgrade to 16G RAM and a 1TB SSD before going on to check the perfs. That's a testament to me of how usable they think the laptop is in its sold state.

Looks like the SSD is about $80 on Amazon.com and the RAM maybe $30+, so that's already a significant fraction of the device's original price.

Still reasonably affordable, though. But it's not under $200.