There's just a boatload of sf/f in general - big-budget and lower-budget both - probably because people are abandoning the theater to get movies on DVD so the smart strategy is to make movies that are "wait-proof" - if you want to see WALL*E, The Dark Knight, The Mummy
, etc., you'll be more likely to get to a theater to see them, versus the less visual/visceral type of movie like some Woody Allen flick. What's the point of bothering with that
before the DVD comes out?
But the really cheap stuff doesn't fit the strategy. You've got to hit a minimum standard before it's worth going to the theater to see.