The only contracts you can't negotiate are government job contracts and union jobs. Which is one reason I'm not interested in either of those job categories.
> bank contract
Haha, I once negotiated a large loan from my bank at an interest a full percent below their official floor. I'm not even very good at negotiating, some people I know are much better.
> telecom contract
Have you ever said the magic words: "that sounds high, can I get this for a lower price?" The salesmen are allowed to negotiate. The initial price they quote you is the sucker price.
Every time I've been to the dealer for car work, all I have to do is balk at the quote and 10% comes right off.
This is not a special skill. Anybody can do it. Fer gosh's sake, you're expected to negotiate.