Maybe I missed something along the way, but we've paid $30-50 or so for the EXPLORE and SCAT tests, $70 or so for SAT/ACT, and $500 (iirc) for a SB5 test when one child was denied admission to the gifted program. NWEA, OTIS, SB5 (for the other child), and others were all free through our public school.

There seem, to me, to be plenty of reasonable options. Don't get a full body MRI/NMR/etc. scan when a simple doctor visit will do, unless there are significant underlying issues/needs.