Say you had a perfect space launch system.

Let's say the regulars around sci.space managed to come up with a
near-perfect space launch system and agree about it being the best.
Let's say
100M US$ to build a system that launches
1000kg at a time
at 5g max accel.,
launching up to 10M kg/yr directly to LEO without a need for a
circularization burn,
at an inherent cost below 6 US$/kg,
a system powered by electricity on the ground, with efficiency above
90%,
low environmental impact,
using continuous power,
and with marginal tourism value.

Unfortunately, the system does not scale down well, so you can't build
a very convincing test model on the ground.

Alright, where would you go from there? How would you go about getting
it built?