Ten years ago five frame sizes (front and rear triangles) cost $150K. $30K sounds awesome. Suggest you start with a 55-57cm, like shoes, bikes tend to look good in a certain size right?
You could vet your geometry and perhaps also create a skeleton for hanging Ren or clay off, by working with a local small custom frame builder. Even with the wackiest geometry and strange features they could get it done for under $5K and probably much less. Once you have a skeleton (or armature would be a better term) you could have machined foam or hell, handbuilt foam shapes around the tubes for a rideable, decent looking prototype.