In 1976, those Theatervision units sold for $1995.
Kiplinger's Changing Times Magazine had an article about them in October 1976, and Popular Science had a similar article (more of a how-to) in November of 1977. Both are available on Google Books, full view.
I remembered the PopSci article from my teenage years - I had an ex-hospital Sony 17" set I so wanted to convert, but had no room in my 12X14' bedroom...never did get to build the "Personal submarine" either...
