For $107 it's debatable ... for $59 I hardly think you can call this a rip off. That's the equivalent of saying any type of disc based media is inherently a rip off because you can illegally download it and watch it for free. If that's what you want to do, then by all means go ahead ... free country.
However, there are a couple points to consider ... it would be a pain in the ass to find every single episode in dvd quality and download it to your computer. In addition, in 10 or 20 years who knows if this will be available via streaming sites ... but I'll still have this DVD set to share with my kids. And finally, the exclusive disc and booklet this comes with can't be found elsewhere, so it's a nice exclusive.
But really, if you think this is a rip off, why are you posting about it? If you aren't a big enough fan of the series to at least have a passing interest in this set, then why complain and call it a rip off when it's on sale for nearly half the msrp. Just a thought ...