question

It is better not to trust anyone given the circumstances, if the client starts entangling things, it is a very bad sign, and it is better to forget.
    Working as a cartoonist in an amusement park, I had to learn this by the hard way.
     Every time a client looked for ways to do things outside the procedure, he ended up refusing to pay.
      In the end, when this happened, I learned to ask for payment in advance, and I never regretted doing so.

Applying to "public" projects here (on CGT) is a "meaningless exercise" at all. Because "customers" always trying to get something that demands lots of time, but they want to get it "yesterday ASAP" and with price of generic stolen model. :) And when you are focused on project, you are losing your time in terms of models promotion and as result you are losing in your sales.

And as said LemonadeCG, never send to customers anything else than screenshots or previously made renders, until they choose you as contractor. If they don't accepting your offer -- just try to apply to another project (if you want).

The logic chain "I will send him brilliant model as my job example, and client will be excited and grateful and will choose me" don't works here.

Thanks alot
For the reply

You should never start working on the project, untill client will chose you and prepay money (you will be informed about that by an e-mail). If client insists otherwise, then it's almost certain that he wants to screw you.