How to get the DLC's for Civ 5 on Steam?

I just got Civ 5 on Steam. It's the first time I've ever played Civ. I was wondering how I could get "A Brave New World" and "God's and King's" and stuff like that, without buying the entire game again?

I looked in the steam store and it seems like I have to spend another 30 dollars for the DLC content? Is there no cheaper options? Do I really have to spend the same price as the game for each DLC I want?

On humble bundle you can buy the complete edition for 10 euro's which is provided via steam keys:

https://www.humblebundle.com/store/p/civilizationV_complete_storefront

I believe it includes all DLC's, but you can/should check it out.

Edit: Remember that it is a sale offer which is valid for 1day and 7 hours.

Wow, that's awesome. Thank you.

It's also on sale on steam now (Complete Edition, 9.99)!