Have you seen results with paid experiments at this early stage? One thing we are considering is to do a paid masterclass (low ticket) and run paid ads for that. Bring them in the funnel and get them signed up to use the product.
So, usually paid experiments won't really give you a return at an early stage, but occasionally they can if you get lucky, but at least they'll give you an idea of what your CAC can be, and give you a starting point to start optimising it