I think the question of whether or not it's worth it depends on why you are buying the bat. If you are buying it because you want to improve your batting average, I would agree with Tim and say that you're better off spending the extra money on coaching and settling (if that's the right word!) on a £250-£300 bat. However, if you want it because it will make you feel good, and look pretty damn cool, then I'd say the Screaming Cat is a good choice!
Does someone buy a Ferrari because they want to improve their driving? I'd say not. If this is a Ferrari type purchase, I would say go for it! You only live once!
Never really thought about it that way, but I completely agree!
Here's something completely unrelated to cricket, but of a situation where I can relate. (ish) I managed to urge my parents to buy me a new grand piano to replace my old piano, as I felt I was getting to the point where I really was starting to enjoy my music, and wanting more out of it. At the back of my mind, I think I was wanting a grand piano as they looked really nice and play much nicer than uprights, kind of like why you would buy a SCat, because it looks really nice and you know they will perform really well. (The old grand was dying, so I had to use the upright) After getting the grand piano, I guess it was motivation to get even better at piano, therefore I found myself spending hours on it. I don't think I had ever improved as much as I had in the first year of having the piano.
I honestly believe that buying the piano wasn't what improved my playing, but it was more my mind set to improve even more to get more out of the piano which helped me improve.
All depends on the reason, and your mindset of course.

Essentially, a bat is something which should help you get runs, and the only way you can get the most out of it is by improving your game. Having a great bat doesn't make you runs, but it can certainly help if you learn use it right!

If it helps, I made my high score using an Asian made bat, and not even a bat made by Julian Millichamp could have stopped me from getting out as I attempted a pre-meditated sweep to a yorker!