Need help on how to build my own unique TF.

This could be my most ambitious project. TO MAKE MYSELF!
But how to proceed so it will not be overly complex or expensive to do? The robot mode could look like anything, as long as it's rad looking and is fairly humanoid in shape. Also, his Snow-Plow convert to his sheild and some other part convert to his axe.
And the most important is the vehicle mode, a motor-grader with snow-plow. the vehicle mode should be perfect looking. Just look at my signature and you'll get the idea of what I want to do.
I could start with a 1:50 KOMATSU GD 655 MOTOR GRADER model... but these things cost more than 80$ apiece! A model kit would be perfect, but they are expensive too. And how about joints? Can it be made uniquely out of metal? How to make all the panels fit together seamlesly and solidly?
I also don't want to use any Transformers parts, if possible.
Help?
But how to proceed so it will not be overly complex or expensive to do? The robot mode could look like anything, as long as it's rad looking and is fairly humanoid in shape. Also, his Snow-Plow convert to his sheild and some other part convert to his axe.
And the most important is the vehicle mode, a motor-grader with snow-plow. the vehicle mode should be perfect looking. Just look at my signature and you'll get the idea of what I want to do.
I could start with a 1:50 KOMATSU GD 655 MOTOR GRADER model... but these things cost more than 80$ apiece! A model kit would be perfect, but they are expensive too. And how about joints? Can it be made uniquely out of metal? How to make all the panels fit together seamlesly and solidly?
I also don't want to use any Transformers parts, if possible.
Help?