Auphonic is definitely a hidden gem in the podcasting world. It can’t do the editing and snipping and splicing that Audition or Audacity can, but in terms of filtering and post-processing, its pretty much magic.
These are just a few of the remarkable tools for creating podcasts but there are many out there. As you can see, podcasting isn't costly. Perhaps what's costly is coming up with the ideas because that needs a lot of brainstorming and involves a lot of thinking, but the rest ...