I am sure the open source tools exist to do all of that, but the labor to put them together has value that is dependent on the context.
Then there are other open source packages, which may have everything desired, and which The Google can find e.g. see here:
https://modbusscope.readthedocs.io/en/stable/index.html
Something like Ignition may seem expensive in comparison to free software, but there is also a saying: I cannot afford free software.
Sorry to question the question, but please define expensive and what the labor costs are.