Bullshit. SpaceX dropped the launch cost, which is far away from the overall mission costs that NASA has to deal with. Dropping the launch cost means decreasing the cost of red tape and infrastructure (such as using fuel stored at higher temperatures), and increasing modularity and benefits of scale but it doesn't help decrease the cost of R&D and manufacturing of satellites and mars rovers.

NASA uses the RAD750 [1] as well as a few other still in production CPUs. Remember Voyager? The satellite is still flying and sending back priceless data after many decades? To launch missions (and critical infrastructure like GPS) you need years, decades even, for usage & reliability data to accumulate and industry to perfect the manufacturing process of parts that can handle environments that are, by any definition, at the extremes. But, please, show me a mission launched in the last 5 years with a 50 year old CPU design.