Although many of the high tech colorimetric analysis machines are great, there is additional cost in reagents, and tech support. And price sometimes reflects accuracy, and reliability.
I used a multi-parameter reader that ran about $20,000 when I worked in a lab.
There were separate reagents for each of 200 tests (nitrate, alkalinity, difference metals, etc) that had to be fresh. A DI blank, a Standard, and the sample all needed to be run for each test, and monthly tech support was needed which added exponentially to the cost.

some of the pro strips available from companies like Fisher Sci, would be a better choice for most aquarists

Being under a water conservation restriction, the saving of rain water would be a high priority for me, and it was, even though where I lived before, water was plentiful.