The VCR's are probably cheaper on Ebay than the actual VHS tape! LOL.
The production company that made the Senna documentary must have gone out of business.
Otherwise they would have remastered it for DVD given the success of the recent film.
And if you do end up getting the VCR get a copy of Murray Walker's Fantastic Momments. Outstanding! That was real F1 !!! not this remote controlled stuff now.
That film has the last laps of Senna v. Mansell going nose to tail the whole way at Monaco in 92. And a bunch of stuff from the early 80's like Gilles v. Arnoux.
Amazon.com: Murray Walker's Fantastic Moments [VHS]: Murray Walker: Movies & TV