The Effect
See here for the review request that contains the description.
http://www.talkmagic.co.uk/ftopic11466.php
Cost
Around the £13 mark but as always, depends on where you buy it

Difficulty
(1=easy to do, 2=No sleights, but not so easy, 3=Some sleights used,
4=Advanced sleights used, 5=Suitable for experienced magicians only)
In principle it's a 1 although it rrequires some care, the right materials (widely available) and of course some experimentation before you're ready to perform to others.
Review
I was intrigued when I first read about this effect and came acoss it whilst browsing through a number of other titles.
It's a DVD that's put together well, the teaching is extremely good and the effect is both cunning and grizzly. This WILL have all but the most die hard of your specs squeeming

Obviously this is going to be best performed with other 'geek' type tricks and would look right out of place before and after an ambitious card routine so either pick your other effects carefully or just do it as a sort of 'hit and run' presentation.
If you performed Saw with other 'geeky' effects such as coin in soda can, Third Degree Burn, stigmata etc. then people would be seriously worried about you

There are three other presentations of this effect that are also included and that includes a presentation with a lifesaver (Polo in the UK) where you swallow and then retrieve through the next on the thread. The sleights required are well taught and it adds variety.
I haven't perfected it just yet so I'm waiting before I spring this on an unsuspecting audience

You will get requests to 'DO IT AGAIN' but the performance can't be repeated to the same specs immediatley which I think is a good thing.
Overall
I like it - it's not impromptu but it could be made to look as if it is.
8.5 out of 10