Using materials obtained outside the Earth's gravity well, we can make much larger ships than if we have to launch them from the surface of the Earth. Of course that requires some kind of materials processing facilities in space, which is depending on stuff like Moon bases and the years of development of materials science in low and zero-gravity environments possible in those.

Further, the Apolo Program has most definitelly shown we can buy progress. Not "beyond the known principles of present day science" progress (so, no amount of money is going to get us FTL travel) but certainly Engineering progress (so solar sail towed asteroids, moon mining, moon-based nuclear reactors, mass drivers to push loads from the Moon surface into orbit, alternative ship designs using materials found outside the Earth's surface and/or low weight designs such as the insuflable space stations that were at one point suggested and even test at a small scale, and so on).

It wasn't by chance that what I suggested was asteroid mining and Mars stations rather than interstellar travel - the money wasted in the Iraq invasion alone over the decades since could have built the infrastructure needed, to get the engineeringe experience required to be able to do the former, not the latter (as that indeed requires a kind of progress that we cannot buy).

Instead, we have Facebook, over the counter credit derivatives and LLMs.