So, does the existence of open source code mean that paying for anything is unnecessary? (Taking a statement and turning it into a ridiculous absolute, sorry).

Yes, free software exists. The people who made it chose to make it that way. This does not mean that everyone else has to make the same decision. If I were to choose to give you one of my sculptures for free (doesn't really exist, it's just an example) that would not mean that you could then demand that all other sculpters give you their work for free.

Same with software. If you don't like that LimeWire costs $$, don't get it, get one like Gnucleus that is free. Do that, but don't demand that LimeWire be free as well. Or get a clue, and realize that it really is if you would just visit the CVS