At $1500 a developer (or $4500 if you need iOS + Android licenses), Unity3d is a steal. Plus you can happily develop with the free version until your company is making 6 figures in revs. The free version is lacking some features but until you get really serious about Unity you don't really need it.
Non-commercial use: free
Commercial use for in-house applications (e.g. training simulations): $2,500 per-seat
Commercial use for end-user-oriented applications (e.g. game development): $99 plus 25% of royalties above $50,000
Full terms: http://www.unrealengine.com/udk/licensing/commercial_license...
For anything but not-successful games the 25% royalties is going to be a lot more than just $1500-$4500 up front per dev. I'll take the Unity licensing scheme any day of the week.
Oh well. I stand corrected :-)
Maybe I was thinking of Xamarin's license costs instead ;-)