DemoWolf tutorials are available in "series" of several related tutorials, and the cost of each tutorial series varies depending on how many tutorials are included in the series, how complex they are, whether they include voice, etc. Furthermore, you have the option of either "buying" the tutorial series, or subscribing to them. When you buy a series, you pay a one time fee for us to brand them with your logo and provide you with the completed tutorials. When you get a DemoWolf subscription, you pay a much smaller monthly fee, and have access to upgrade your tutorials whenever new releases are made available, or if you ever need to change your logo.
A typical tutorial series may cost anywhere from $50 to $200 to purchase outright, whereas subscription fees are $9.95 per month for one series, $19.95 for any 5 series, or $49.95 for unlimited use of all 100+ series (which would cost several thousand dollars to purchase).
For the most part, the subscription service is the better deal, as hosting applications tend to need upgrading often. With a subscription you never have to pay for upgrades, whereas with purchasing you would have to buy the new upgraded series when available (if you want).