ADV/Travel market appears well flooded with content ATM. The Internet's made every "Johnny Adventure" an expert, giving them a stage upon which to perform. With no vetting, the internet creates "The Cult Of The Amateur", and anyone can put up a story or film ... may even make money at it.
But most ride reports/vids are well intentioned amateur efforts.
"A for Effort" does not sell the book or film.
Selling price? Not the right question to ask at this point. First, have something worth seeing/reading ... get good reviews and distribution. Let's see a trailer!
That said, real talent will always rise to the top ... and get noticed. Eventually.
How much time you got?
But not everyone can write lyrically, tell an original story with a twist or capture a reader.
Film making, IMO is even tougher to do well.
Distribution is another worry. Unless a writer or film maker has a powerful resume of work, he/she may run into some bumps in the road. Baby steps to get there.
Ted Simon hit a home run first time out with Jupiter's Travels
... but had a decade writing at the news paper and was "pre internet". Lois Pryce's Lois On The Loose
came 30 years later ... it was cheery and funny .. Lois had worked at BBC doing media, she's witty and just plain smart. No idea if her Beeb connections helped get her book on the shelves worldwide?
Austin Vince's Mondo Enduro
and Terra Circa
now look like charming "old school" semi pro efforts ... but somehow deliver(ed) the goods. Funky but fun to watch. Not much else like them back in the 90's. All the key elements of a good documentary were adhered to. (mostly!)
Long Way Round
worked due to celebrity appeal and corporate backing/distribution ... and good editing! Most haven't a clue just how important editing is. I was in film school 4 years ... never got close to being good at it. You either CAN or your CANNOT edit. Can't be taught. (unless you're cutting news or "reality show" horseshite, which doesn't count!
) A good script and a smart cameraman make a BIG difference.
So as said above: content is everything. And quality. And intelligence. And excellent camera work, sound, music ... and editing!
Price? If it's good ... then "whatever the traffic will bear".
Go for it!