If it's a simple water bottle design with 2 holes, the quote will be of 50$ for making the 3D CAD as well as the pdf files. The quote might vary according to the complexity of the project, ready to sign a NDA as well as an IP agreement before discussion and since i think you will be 3D printing the prototype, can also provide gcodes for 3D printing yourself.
I am a mechanical engineer with 8+ years of experience of product development using CAD/3D Design(Solidworks) and FEA/Analysis(Ansys). I've made 200+ products on freelancer for mass manufacturing as well as job manufacturing and have a thorough knowledge of material science, rapid prototyping, 3D printing, industrial designing, traditional and advanced machining processes. Being awarded the title of preferred freelancer by freelancer.com, with my good communication skills, technical knowledge and out of the box thinking i can provide the best result from your input.
Along with CAD models, I can also provide technical drawings and general arrangement sheets for manufacturing as well as realistic renders for illustration purposes.