I was looking at the Unity site, and I was a bit confused with the pricing. It says it's free, but for iOS/iOS Pro or Android/Android Pro. I need to shell out $400 minimum each. So if I want to develop with Unity for Android and iPhone, I need $800 to do this? (not saying that it's a lot of money, actually seems reasonable, just wondering)
Yes, the engine is free for Win/Mac/Web. But if you want to release on Android/iPhone you have to buy some extra license. But I agree with you. It is a bit confusing, because on the download page it says "Free Full Version for Windows with Unity Pro and Android." They don't mention that it is a 30 day trial. At least, that was the case some time ago...
There are certain restrictions in regards to commercialization of products that apply to the free version of Unity. I believe you are allowed to profit up to $50,000 for a product produced by Unity before you need to purchase additional licensing.
It is pretty steep to purchase Unity Pro and the additional add-ons if you are just starting out and your on a shoe string budget. There are also some student licensing options to consider. The student pricing is for annual licenses and they only cut the current prices down by half, which if you are planning to be developing in Unity for longer than two years it is not really worth it.
Best solution is to download Unity and get your game up and running to near perfection, then download the free trial and spend the next month perfecting your game on your platform of choice. When you have completed your test deploy and your trial runs out, your best bet is to decide whether to bite the bullet and purchase the license. If you decide to try your luck then you can try to recoup your investment by selling your application (400+ friends at 99 cents should do the trick), but there is lots of competition on the app stores.
Since May 2013, the basic license to publish for Android and iOS is Free. This was a move to remove the costs of the basic license similar to the move that made basic Unity License free of charge for PC, Mac and the Web in 2009. See https://thenextweb.com/insider/2013/05/21/unity-makes-its-android-and-ios-video-game-publishing-tools-free-to-small-and-independent-developers/
However, depending on your needs you can check license upgrades.