Sure but it's not mainly the R&D, it's the capital cost of such large, complex reactors. MIT's ARC, to take the most conservative alternative, is also a tokamak, but with much stronger superconductors it can be built a lot smaller and cheaper.

MIT has a lot of experience in this area since they already have a tokamak with the strongest magnetic fields of any in the world. They've made at least one fundamental breakthrough with it, not too long ago. Of course Congress is about to cancel their funding.