Is your primary purpose low light video? If so, you want a wider aperture lens. I know it's not 30mm and may be too long for what you want, but the 50mm f/1.8 is going to be the cheapest solution, and will deliver great picture quality with a wide aperture for shooting in low light. The 50mm f/1.4 for a little more is a great lens also.
More in the range you asked about... If price is not an issue, the Canon EF 24mm f/1.4L is an awesome lens. I've rented / borrowed but don't own one myself because price is an issue, and this is a very expensive prime lens. Some more affordable lenses in that range you might consider are the EF 24mm f/2.8 and the EF 28 1.8 USM.
It all comes down to your basic uses, personal preference and your price range. Just remember that the old saying, "you get what you pay for" isn't always true. Ten times the price doesn't always equal ten times the lens, and there are some great lenses out there (especially primes) that you can get for cheap.