The Pi 5 costs around $126, not including the SSD or case...
The Pi 5 8GB is $80. Where is the extra $46 if they aren't including the case and SSD? Taxes at 20%, which is generous, would only increase the cost by $17 if they are including the $5 fan. That means shipping would be around $24, which seems a bit high.
I'm not sure. With official cooling and PSU it's about $100 before taxes and shipping. I know the n100 mini PCs are cheaper than $187 as well. Could just be their particular country/region and setup.
From everything I've read the Pi 5 made massive strides forward. It's a great SBC and a NUC is still your best bet if you need something beefier. That the Pi has closed the gap and even overtaken N100's only means that N100s will get cheaper which is great for consumers.
Even though the board itself is only a bit larger than the pi, the pi uses tiny amounts of power and if you need less, just buy the Zero. When you run windows on it the PSU will be more expensive than the computer.