Sorry, my original answer was a bit misleading.
Sound Forge is much like CoolEdit in some ways, but it's not quite as simple as it being another developer's implementation of the same tool. There are also the full and "lite" versions to consider, which further complicates the comparison.
CoolEdit Pro is a multitrack recorder/editor, which is a significant difference from Sound Forge, which works on just a single mono or stereo track. Their similarities lie in the depth of detailed audio data editing available to you, and their prices are somewhat comparable.
CoolEdit 2000 is a stereo editor. But it doesn't have the same depth of features that would allow you to compare it directly with Sound Forge. It does compare closely to the "lite" version of Sound Forge, though -- I think it's called Sound Forge XP -- both in feature set and price.