There are different lines of albinos for boas. Kahl doesn't hold its color very well as an adult, where Sharp really does. So basically Sharp is just a better line of albino. I personally think $250 might be a little much. Browse kingsnake and you can find sunglows for not much more.
You are correct that Sunglow is an Albino Hypo. Sharp sunglows are much better looking than Kahl, and more expensive.
Oh, and beauty is in the eye of the beholder. So you might actually like Kahl's better. I just had to add that. Personally I like quality, so I like the Sharp strain.