I love the product, it has great potential. I would pay $10 to create a tutorial personally and $50 as a company.
I'd charge based on number of tutorials. For upto 3, it's free but your branding is there. For upto 20 tutorials on your site, it's $30/month or something. You get the idea. This ensures if some massive site is using you for hundreds of tutorials, you get paid for the value you're delivering.
Of course, pricing is a dark art so take these thoughts with a grain of salt.