I wonder if they will sell you more than one Raspberry Pi Zero? The Zero is advertised as being $5, and it makes me angry every time, because it's not possible to buy it at that price. Every Pi retailer either has a one-per-customer limit, and charges shipping, or, charges up to $15(!) per Zero if you buy more than one. So it's essentially a $15 device being advertised as $5. I shouldn't be so annoyed about it, but I…
High-demand cars often sell for well over sticker price. A few recent examples are the Civic Type R, the Focus RS when it was 1-3 years old, the BRZ when it came out... Demand is higher than supply, and vendors (car dealers in my car reference) are profiting from that.
I understand your outrage, but the fact that multiple vendors are selling at this high price means that the market is saying the product is worth it. If you choose the perspective that the Zero is a $15 board which you can occasionally buy for $5, you can be free from spite and simply decide if you want one. Ten bucks and a slightly different perspective is a small price for tinkering and being free from anguish!