g-max...
you might consider making addon packs for known games which you can sell as shareware or what have you to build capitol for developing your game.
g-max is free and uses the graphics engine/rendering for games like Quake and such.
http://www.discreet.com/products/gmax/

Gamers:
Want to create and play your own 3D character in your favorite video game? Now you can!
gmax is a free 3D modeling and animation tool based on Discreet's award-winning 3ds max™. Built for gamers to create their own in-game content for gmax ready games, a gamer can produce everything from characters and vehicles to landscapes and props. Not only do you get to customize your games with gmax, you also learn 3D design within a professional-level tool. gmax - build the worlds you want to see, in the games you love to play!
Game Developers & Publishers:
Design and Sell Better Games with gmax in your pipeline. Join Discreet sparks, and use the API and tools to extend your game with custom game packs – find out more. http://www.discreet.com/products/gmax/gmax_dev.html