I think dr b you are falling prey to the falisy that you can extrapolate future technological advances from past.
When you're in the midst of a period of scientific advance thats very tempting but for example in 1850 trains reached 78 miles per hour, by 1950 it was 715 mph, a few years just after the year 2000 a nasa test vehicle managed 7,000 mph
At that rate we would expect 70,000mph by about 2050 - Dont see that happening do you?
What tends to happen is that fundamental technology changes happen - steam, propeller aircraft, jets rockets and things progress very rapidly to the limits in those technologies.
However such paradigm shifts are not inexhaustable and there's no telling when they can come - "low" temperature superconductors looked imminant in the 80's but they never made it mainstream - they may now be about to happen but we're still talking liquid nitrogen temperatures not room temperature.
I also don't think 2 million dollars is much of a prize! I doubt you can build a Lear jet for that let alone a space elevator! the money is in any patents.
I'm not saying it's impossible - just that I first say this talked about in the 80's (although it's older) - I'm not expecting to see it in the next 50 years