so who will cover production cost of those videos?
The person who is selling / offering their services covers it. My idea is the same thing as free to play games. The idea is basically that instead of charging people money upfront like we traditionally have done, why not just offer it for free? Then let the people use it and try it out and if it works and makes them money, then they would have to pay the company/seller the % they owe (you could stipulate a % fee in some contract before accepting the free service/product).
Free to play games basically let anyone download and start playing their games for free. Then what happens is if the players really love the game and get addicted to it, they will come to realize the only way to really climb the rankings and get better is to start buying in-game items/services to help you advance and to compete with your rivals. It's a brilliant strategy that works for both parties and is a win-win.
So in this particular instance, people who are offering you videos to make you rich on youtube (or any other social media platforms) but first you have to pay them $5000 or $10,000 is very old school method IMHO. It would be better if they offered to make me a free video (but to receive the free video they would make for me, I sign a contract that would state that whatever amount of revenue I earn from it, I'd have to owe them back X %). So this way, if there video actually did work well and brought me a million views and $7K in revenues, then I could pay them the X % as stated in the contract.
Of course, if it was this easy for the seller to make videos that can make so much money and views, they wouldn't be selling it in the first place. They'd just post the videos themselves on their own channels and reap 100% of the revenues. What they are banking on is that for every 1 person that knows how to use it right and make it go viral, 100 people will not succeed. So that's 101 sales they made which is good profit for them instead of 101 successful videos and reaping in % from each video.
BTW, this is not directed specifically to this seller. I am just merely stating this in general to all businesses. If their products and services are really true and work as they say it will, then why ask for $5k up front? Just give it for free, let a hundred people run your videos and then start reaping a % of revenue from each of those 100 people who used it.