Apparently from his webpage it looks like it was all just a hobby until he found a bankrupt firm that used to be selling all kinds of vacuum stuff (pumps, valves...). He bought their stock, refurbished it and sold it and got the money to start pursuing his dream.
Also he is from my country, so I might be kind of biased, but I love that someone still here has got the balls to start such a niche business.
BTW, could you build something like an animated neon sign, but instead of neon tubes use one huge nixie with just wires for the patterns?