Why can’t we afford to properly test the potential monster breakthrough of EMdrive or other possible breakthroughs ?

Here is the 712 page breakdown of NASA $18 billion 2017 budget which provides only a few million for Advanced concepts and innovation projects and has not budgeted a launch of an EMDrive to Space Station.

$2.7 billion to operate and manage facilities on the ground.
$1.78 billion on Earth science
$1.45 billion on Planetary Science

Of course there is a lot more waste and inefficiency in the $4 trillion federal annual budgets.

Although NASA conducts a much more visible space program, DOD’s space program is larger. There is no easy way to track national security space funding since “space” is not a specific item in DOD’s budget. A portion of these activities are classified (“black”) programs for which budgetary information is not available on an unclassified basis. The rest of the funding is for unclassified (“white”) programs, but is spread throughout the DOD budget in research and development, operations and management, and procurement accounts for the three services and defense-wide activities. The majority of funding is in the Air Force accounts, but is difficult to identify except for major programs. According to the fiscal year (FY) 2011 edition of the annual Aeronautics and Space Report of the President (the most recent available), DOD’s FY2011 space budget was $27.3 billion, which is thought to represent all spending (classified and unclassified) for national security space activities

DOD’s unclassified space systems include the following programs, some of which are operational and others still in development or earlier phases:

Communications Satellites: Defense Satellite Communications System (DSCS), Wide-Band Global Satcom (WGS), Milstar, Mobile User Objective System (MUOS), and Advanced Extremely High Frequency (AEHF).
Navigation Satellites: Global Positioning System (GPS)
Early Warning: Defense Support Program (DSP), Space Based Infrared Satellite System-High (SBIRS-High), Third Generation Infrared Surveillance (3GIRS)
Weather: Defense Meteorological Satellite Program (DMSP), Defense Weather Satellite System (replacing the National Polar-orbiting Operational Environmental Satellite System, NPOESS, which was a joint program with NOAA and NASA)
Ballistic Missile Defense-related: Space Tracking and Surveillance System (STSS, formerly SBIRS-Low)
Launch Vehicles: Evolved Expendable Launch Vehicles (Atlas V and Delta IV), Pegasus, Taurus, Minotaur (all of these also are used by the civil space sector)

In 2015, $500 million went to training Syrian rebels. The government had vetted, trained and equipped only 145 fighters, including just 95 who had returned to Syria to fight. That worked out to cost of roughly $2 million per trainee.

The Pentagon could easily save $125 billion per year based on a Pentagon funded fiscal analysis. The Pentagon has buried an internal study that exposed $125 billion in administrative waste in its business operations amid fears Congress would use the findings as an excuse to slash the defense budget, according to interviews and confidential memos obtained by The Washington Post.

Pentagon leaders had requested the study to help make their enormous back-office bureaucracy more efficient and reinvest any savings in combat power. But after the project documented far more wasteful spending than expected, senior defense officials moved swiftly to kill it by discrediting and suppressing the results.

The 77 page report issued in January 2015, identified “a clear path” for the Defense Department to save $125 billion over five years. The plan would not have required layoffs of civil servants or reductions in military personnel.