Pro versus Free

http://unity3d.com/unity/licenses.html

Pro has render to texture, for reflective water and things like real time arena-like viewport screens, as well as realtime shadows, version control, and a profiler which helps you pinpoint what is using resources for optimization. More importantly, it has post processing effects, like glow, motion blur, edge detection, and color correction. Also Pro has no watermark upon startup of your game.

Asset bundles are also worth looking into, as it is a Pro only feature that may be required for your game.

In the end Pro is not necessary for creating a quality title, though it will add a polished look to your game. Is it worth it? That depends on your budget, though $1500 is not asking much.

Also, now is a good time to buy, as the cost is reduced to $1200 for a limited time, and you will automatically get 3.0 when that comes out (as well as early access to the 3.0 beta when that becomes available). Just something to think about.

There is a 30 day trial available for Pro if you are still on the fence and want to try it out.

I'd say it's absolutely worth it. Think of it this way: Getting Pro is what gives UT the money to keep on developing this incredibly great time and money saving tool.

Of course, if you just can't afford it - you just can't afford it, and then it's great that you can use Unity for free as well. But if you ask whether it's worth it - I'd say: No question, it totally is. Every single cent!

This is a "want or need" answer.

Life has a habit of turning corners and going off in unknown directions. You may not "need" Pro now, and may may never "need" it. However, since turning life's next corner may change your needs, think about this:

If you have the money available now, and you'll still be able to do things you're accustomed of doing, like eating, then buy Pro while the funds are available. You will be happier having the full toolbox even though you won't use every tool today, but you'll be sad if tomorrow you don't have the funds but need the tools.

If you don't think the economy will affect your ability to buy Pro down the road, then go Free for now and wait till you definitely need Pro. If there's any doubt, get the full toolbox while you're able.

as an addition to dhendrix's answer, in unity 3 you will get a great lightmaper called beast and umbra for occlusion culling. these two cost $130,000 themselves but they are free in unity pro. you pay just $1500 and get these and alot of other things. if your game does not need any of those features and your budget is very limited don't buy the engine but if you can unity is the most valuable tech that you can buy. features are like expensive engines and it's really productive. i myself will buy it when i can, even if that time would be 3:00 AM i'll fire up my PC and will buy it. i hope that it will happen soon.

A question. Would Unity Pro be an advantage to a beginner? Or should I learn Unity and Unity code better before I upgrade?