In the grand scheme of things, I think it all depends on how much you interact with a db. If you just run an odd command here and there, $30 may seem like a lot. If you work with databases for an hour or more a day, this could be a huge time-saver.
I am interested to see how "version 2" of this pans out.
For the record, workbench is not the end-all. It is quite clunky.
How is it possible anyway? Queries in source files almost always cannot be executed as such, because of placeholders/parameters. Or what am I missing?
For example, if your price per hour is $20 and this tool saves you 1.5 hours of time in your lifetime, it would make the business case. Or, if your price per hour is $5 and it saves you 6 hours in your lifetime it also would make the business case.
However, it would be a bad investment if your price per hour is $5 and it only saves you 5 hours in your lifetime.