If you just want to try it's free:
http://unity3d.com/pages/create-games?gclid=CNn4_OHL07wCFSYO...
And $1500 is not expensive for a game engine, or really any type of professional content creation tool.
And $1500 is not expensive for a game engine, or really any type of professional content creation tool.
The free version is very capable and unless you make more than $100K dollars with it, you don't have to pay.
"Unity Free, which include the free platform add-on products, may not be licensed or used by a commercial entity with annual gross revenues (based on prior fiscal year) in excess of US$100,000, or by an educational, academic, non-profit or government entity with a total annual budget for the entire entity (based on prior fiscal year) in excess of US$100,000."