I'm not an expert in this area at all, so I pulled that comparison out of a few different articles and wikipedia.
According to [1], the pressure inside the LHC is somewhere between 10^-11 and 10^-10 mbar. That's between 10^-9 and 10^-8 Pascals. CERN also says that it's "a vacuum almost as rarefied as that found on the surface of the Moon." According to [2], pressure on the surface of the moon is between 4x10^-11 and 8x10^-10 Pa. The upper limit is quite close to 10^-9 Pa, so let's say that CERN can manage 10^-9 Pa on a good day.
According to [3], the inside of a nebula is 100-10k times more dense than general interstellar medium. (The "10k particles per cubic cm" figure also comes from the same page.) According to [2], interstellar medium in the Milky Way averages between 10^-15 and 10^-14 Pa. So the pressure inside a nebula should be between 10^-13 and 10^-10 Pa. Another comparison using the number of particles per cubic cm [3] yields a figure between 10^-14 and 10^-12 Pa. The difference is probably due to temperature, but anyway both results are significantly less than the LHC.
We can probably make better vacuums on a smaller scale, though.
