If you do not own it and intend on having a preservation project, then yes, you should buy it. Just because it isn't great doesn't mean it isn't good. More importantly, it's the right thing to do.
I must be the only person who thinks Serenity is mediocre, closer to Starship Troopers than Star Wars. I had no preconceived notions going in and came out feeling no different about the myself, the world, or sci-fi. I'm not saying it was bad, but it wasn't worthy of all the fan-boy hype heaped upon it.
My Two Dicks words by Don Geronimo Sung to the theme to BEWITCHED
They're my two Dicks, oh yes they're my two Dicks
First there was York, such a dick Then I changed to Sergeant, hey what a trick
I love two Dicks, they're great to have around I'm always smiling -- with two Dicks why frown?
I'm the witch with the most fun -- can't you see Just one more Dick--and I'd have three
They're my two Dicks, oh yes they're my two Dicks And come what may, I'm proud to tell you this I'd pass on a love-filled night with the New York Knicks 'Cause I am the witch with two dicks!
I have to vote for Blazing Saddles, but Silent Movie is positively brilliant. How he ever got that movie made is beyond me. It's the most genius work in his repertoire to be sure.