Anyway, I guess my point is, perhaps you should consider skipping the last two? 
It's about time someone proposed this to the Rifftrax creators! Good show, Edward, bloody good show. 
Nah, lots of folks seem to really love them, so I'll just not buy them and everybody's happy.
You mean
we'll not buy them and everybody's happy! Thrifty, feel free to not buy with us.
I don't know, I've just gotten the vibe that over the last several HP riffs, the "Not-Buyer's Club" has been growing slightly. There's various levels of HP Rifftrax consumerism:
1.) Never liked 'em to begin with. *Hiss*
2.) Liked (one of) the first 2
3.) Liked 'em up to Azkaban or Goblet of Fire, but worn out by now. "Does the world really need 8 HP riffs?"
4.) Liked all of them so far
5.) Determined to enjoy every Harry Potter riff, even before they riff it!
6.) Opinion on HP is irrelevant. "I need my Rifftrax fix & will buy whatever new Rifftrax they release!"
I'm somewhere around #3.