[fake-name]

Primarily size. The $10 ebay nixies are tiny.

If you can find 2-3" digit size nixie tubes on ebay for a substantially better rate then these, I'd be very, very surprised.

[hatsunearu]

Yeah the IN-18 which I think is the big kind goes for like 180 bucks each.

These ones are 145 and they are stupidly (in a good way) humongous. I want to try building with these, if I'm honest, wow.