Because the data we get from ebay is not clean, and if you ever take a look at ebay listings, they really aren't the best. People have no idea how to post stuff, so yes, I have a bunch of scripts and filters, etc, etc , etc. But then even after I do that, I still don't find everything. Its not like its a perfect 1 to 1 exact match of set to value. Do you have any idea how many people put New sets listed as used and vice versa? I would say that 50% of the listings need to be reviewed. Do you want data or do you want good data?