In short, it may not be 1.5M but similar amount will be needed.

Excluding all the R&D cost, certification etc..... To buy the components, manufacturing and have extra parts/device stock for warranty purpose will cost the most of the above funds.

R&D and moulding won't be cheap. Certification won't be cheap.

I don't know what is your definition of getting off the ground. If that means concept design or deliver some high quality legal commercial product to the hand.