Why are current probes so expensive?
I believe there are two components at play here:

1 - Clamp-type current meters are much simpler devices because they only need to measure the amplitude of an AC current at a particular low frequencies (some measure DC, but are more expensive). Current probes (especially those with ability to measure DC) are much more sophisticated, having to provide flat response over a decent frequency range and being much more susceptible to all sorts of calibration problems and drifts.

2 - The market for clamp-type current meters is way bigger than the market for current probes, since it's used by electricians, which is a much bigger universe than the one represented by electronic engineers and technicians.

Hey... maybe there is a market opportunity here. Whoever comes up with a more affordable current probe may find a good market among hobbyists and small businesses.