Hopefully you never need to use it- if you can tie up the opposing character you chose for Duel of Twisted Honor, everyone attacking Shredder Clone gets -2 to their Attack. Is it worth ten points and $80 to have Shark Shredder on your sideline, giving your opponent cause to fear KO'ing Shredder Clone? You tell me...

I can say from using this in my last game that it's def worth the 10 points

It is one million percent worth the 10 points. The $80 I can not speak to, that is a utility value question that people have to answer individually :)

This is a risk/reward kind of deal and given the rules as far as scoring goes, you really have to decide if the risk you take of giving up 130 pts is worth it. This thing pops out on your opponent's turn, giving your opponent the opportunity to hit an easy to hit a figure clinging to four clicks of life. If the shark survives, what is like to be a barrage when it pops, then you have an intimidating win condition. But again, is the risk worth the reward?

I think it is worth the investment (in points, YMMV on the $$$ investment). The Shredder Clone is great at going after all the figures *not* chosen for the Duel of Twisted Honor, the rest of your force (215 points?) should be doing *something*. The incoming Shark Shredder is on a soft/risky click, but it will be a giant with free Elite Sidestep so as long as the opposing force isn't completely focusing fire, you should be able to get some action out of the replacement.