This is more from a quality standpoint than a monetary one.
How do we make this a good film?
a few rules
-yes, the first movie remains canon
-Mikaela and Sam have to be involved in some way, though it doesn't have to be major
-Same plot in broadstrokes: Fallen in the big bad, Megatron is revived, optimus dies, Autobots and military vs. decepticons, optimus lives