Just going to let everyone know that it IS still possible to find the Sigma 8mm on ebay at a reasonable price.  I just picked one up for $449 used.  I found a wedding photographer who bought it as a novelty and quickly realized he couldn't do much with it. ebay id: 190218751360. Oh, and it WAS the DG model.. unike the problems some people have had.

Just a positive post for others like me wanting to shoot DSLR tours on a budget...