so I could reason that my channel is worth $500,000 (100 x $5000).
Clearly the above is wishful thinking,
Thank you for putting "wishful thinking" in there, lol.
Perception of value is definitely a component in any investment purchase, but the basis for the investment is the ROI. Without applying a formula for determining returns, the purchase is merely based on emotions. Ignoring ROI, as a Yachting business, you might perceive TinHat's portfolio as less valuable than a Prepping business, who might perceive it as more valuable because as you said, they would have interest in integrating it into their current business. The problem with social media investing is social media is not by traditional standards considered a business. It may make money, yes, but securing the funds to facilitate the purchase is going to be difficult due to the nontraditional perception.
When it comes to ROI, if your 100 x $5,000 formula had included a digital media CPM conversion, it would have been correct. 100 x $5,000 / 1000 = $500... about what might be spent advertising per month on Boat Internationals website? Multiplied by 12 months and you get $6,000. Eerily what I said TinHat's YouTube channel could be worth. Though this calculation is based on an advertising cost scheme and not a profit/cost model. Point is, if an investor cannot prove ROI it severely limits the value of the purchase. Crown's formula (10 to 30 times the profit) is the kind they applied to Facebook, and it took years of worldwide advertising to sell that. Most investors seek to attain a 10% ROI, but don't often get it, making 10 times the profit the high end of TinHat's valuation, which is why I said his "entity" (portfolio) could be worth as much as $325K. And I use portfolio because his business exists essentially on paper, much like a stock investments business does, and the sale/transfer will be similarly structured.
Speaking of selling though, no, TinHat wouldn't be leasing out his YouTube channel. YouTube owns the channel and grants creators access. When you "sell" your channel, if YouTube approves the transfer, they agree to grant the "new owner" access. What you're selling is basically a right of control (over the access YouTube grants). Not completely dissimilar to the purchase/transfer of a website... you're buying access to control a space, not the space itself. Which, think selling a YouTube Channel is hard, wait until he goes to sell the website.
I agree with you though that anyone looking to integrate TinHat's social media presence into their own business would benefit from creating shared videos to smooth the transition, specifically on his YouTube channel. The real heartbreaking thing is... what else could they buy for the same dollar? If he wanted the top end of 30x gross profit, that's something like $60k for his YouTube channel alone... I would think you could get a lot more than 80k subs for $60k worth of YouTube paid ads, and not have to deal with purchase/transition/multiple channel issues.
But he's selling a business, not just a channel. It's value, like everything else, is dictated by what someone is willing to pay for it. Fascinating topic though, isn't it? To think that YouTube channels, Facebook pages and Amazon accounts are actually worth money now... come a long way from YouTube being the online version of "Americas Funniest Home Videos".