No worries about the restricted extras. It stinks that these thing even need to be thought about, but I guess everyone needs to make money somehow, just some things are more sleazy than others.
I'm impressed that you would be willing to make the switch - I know a number of people that couldn't. And Kudos for you for realizing how much these upgrades end up costing you. Mind you, I have no problem spending money for extra features and better software. But simply changing the UI a bit and adding minor features, isn't worth as much money as many are asking. Not to mention changing file types and restricted use as much as they can (Yes Autodesk, I'm looking at you with GenuineDWG and changing the dwg file type config every 3 years, so everyone is forced to upgrade every 3years).
No, here's an experiment for you that might interest you. It's the reason I first went to Linux in the first place, and brought me pretty far. I shot a video for my brother in law in an armory building, which means bad echo. Add to the fact that I had to shoot from the stage behind the speakers due to the way everything was laid out meant I had extremely bad audio. I looked for months to find a tool to remove some of the reverb, but I only found one, which is still in beta and hasn't been updated in a few years, but as far as I am concerned, it is magic. It is a program called Postfish created by Monty at Xiph.org (the guys who created OGG theora and Vorbis, so they know their stuff).
Here is how you can install it in Ubuntu at least, other distros may have different package managers and different package names. You will be compiling the software from source, which is easier than you think, and should take about 5-10 minutes to do:
1. sudo apt-get install build-essential subversion libgtk2.0-dev fftw3-dev
This install the tools to compile, subversion to get the files, and the gnome development packages and sound packages that are required.
2. mkdir ~/postfish
cd ~/postfish
Creates a folder named postfish in your home, then you go into it (remember tab will autocomplete when typing... I did it by accident while writing the cd)
3. svn co
svn.xiph.org/trunk/postfish
This will download all the source files to your current directory (Which is postfish)
4. make
Watch all the pretty code compile. Don't worry, planning for problems is GOOD :^)
5. sudo make install
Watch the code quickly install
And now it's installed. It's a command line program, and it was never fully finished, so I'll walk you through the usage:
postfish random_file.wav > output_file.wav
That will import the wav file, and the generated audio will go to the output file. Ignore any wisdom error messages. (although I think this is the first time they have popped up, anyone know the cause? I am doing this as a VMware test since I already had it installed, and I needed to verify the dependencies)
Now we get to the gui. One thing I ran into once was that multi-channel audio had both channels going to each channel, so if the audio seems really loud, that must be it. Output shows speaker and output file, if you uncheck speaker it will work as fast as the cpu allows, otherwise it will go real time. The deverb is the tool I love, the interface for it should be pretty self explanatory. Remember to rewind the file to the beginning and replay when all the settings have been tuned so the entire file is correct.
Have fun, let me know what you think.