Question

IDE, build tools, emulator… things that i must pay for them without any choice to replace?

Answer 1

You can use Carbide C++ IDE and Qt SDK and Symbian SDKs, all of which are free.

http://developer.symbian.org/wiki/index.php/Category:Symbian_Signed :

In terms of cost if you plan to deploy
your application commercially you will
need a Publisher ID which costs $200
per year and each time you sign a SIS
file it will cost €10 using Express
Signed and €150 if you use Certified
Signed.

https://publish.ovi.com/info/ :

Ovi Store will sell your app, giving you 70% of the revenue. Registering as a publisher on Ovi Store will cost 50 €.

So, besically, you can get development tools for free, but distributing your app will cost if it is a commercial application.