Then again, putting all one’s eggs in one basket is a poor bet if that basket fails ... sometimes it is better to pay a bit more to achieve a very difficult task. Personally, I’d go with all four, just to learn which one actually does the best job and screw the cost.
Higher taxes are not the fault of the cost of utilizing one or more designs, but of retarded US tax policies playing the zero sum game.
I was being slightly facetious, but yes, it is good to diversify risk. It’s one reason I was against cancelling the Ares I and back then I didn’t even foresee one of the greatest risks of all; leaving ourselves dependent on the Russians for space station access for this long. Ares I would already be flying right now if we had stuck to the original plan. Instead we remain dependent on the Russians for spaceflights and we’ll continue to be dependent on them for a few more years to come. Given the current tensions I would be glad to have seen the extra money spent on Ares I just to take that card away from the Russians a few years earlier.