Important decision, help!

[JPWDW]

Hello people, I have to make a very important decision in less than two days. I need to pay a mechanical engineer with a workshop to build a water screen nozzle I designed for my Fantasmic! in miniature show. My economy isn’t the best and the costs for the nozzle are about $280. The main issue besides money is that the engineer can’t assure me the stainless steel nozzle will create the desired effect. Even tho, the measures of the patent that’s going to be built are supposed to work. I’ve done lots of tests in the computer and with similar artifacts but none have worked.

What do you think, should I pay for the job?

Thanks!