First off:

http://img.photobucket.com/albums/v435/kojirodensetsu/45y45u4u656u.jpg

Ok. So from what it seems like to me (not sure if this is true, but it seems like it) the way unique variants work is there's a single flat chance to get a unique variant. Then AFTER that it selects what kind of unique variant.

If this is the case, what I think should be done is it just be changed so that the chance of getting a unique variant is determined by the buff and not a flat percent. For instance (making these numbers up for argument sake) when you go to make a sword there's a 25% chance there's a low buff, 20% chance for moderate, 15% chance for high, and 10% chance for Ultra. It does a roll for each buff and if one is selected it gets that. If multiple get selected then it applies the highest damage buff one. It doesn't necessarily have to be done this way, it's just an example of what I mean.

So this would mean that there would be a higher chance to get unique variant then there are now, but the high or ultra buffs would be the rare ones.