i bought mine for RM175 from lowyat.
was waiting for somewhere nearer to get it(curve/1 utama) but always no stock

so just went to lowyat to grab one.(i guess if you factor in the transportation it's about Ninja's price )

coming from using a USB keyboard,this keypad takes a LOT of getting used to.

it's pretty easy to switch from controller to keypad to controller,but because the buttons are so small,you have to take your eyes off of the screen to type.
that wouldnt be much of a problem if you can type fast.
but it's hard to type fast because sometimes the keys DONT respond

simple typing like "break" could end up as "beak"

another thing about the keypad is you need to manually(use a usb cable to) pair it with the ps3.
makes no sense why you cant pair it using bluetooth since it uses bluetooth to begin with

works perfectly on laptops.
paired it via bluetooth,and used it as both a keyboard AND a mouse
has a left and right click,too

if you're not in a hurry,this keypad works great.
but if you're in a fast paced game and need to relay information,be prepared to make a lot of mistakes (unless you're fully accustomed to the keypad,then it should be pretty easy )

doesnt work with handphones(no idea why)
can pair,but cant use

final verdict:
pros:
small and light-only adds abit of weight to the controller
doesnt hinder any buttons-play games as usual..you'll hear alot of people say "it's like it isnt there,when you are not using it"-i concur wholeheartedly
bluetooth enabled,so works with other devices as well
in built touchpad
cheap-RM175 for a keypad with built in mouse.personally, i find that cheap(especially since normal bluetooth keyboards start at RM200 )
has a sleep mode-saves battery when device isnt in use
easy to clip on and off

cons:
small-you may have a hard time pressing the keys cos it's small(compared to a regular keyboard that has enormous keys)
touchpad too sensitive-sometimes it's hard to press a certain button on screen,cos the mouse goes from A-Z quite fast.a simple swipe can move the cursor across the screen
only one color so far-black.so if you have a white controller,it'll look abit weird :/ unless you like that sort of thing
requires a mini usb cable to pair with the ps3.weird issue,since you can pair with a different bluetooth device without the need of a mini usb cable
once paired with a different device,you have to re-pair it with the ps3(and vice versa)
has a sleep mode.so far i've no idea how to turn this off.it's annoying sometimes when you need the keypad in an emergency.have to wait for it to wake up(eventhough it's only a split second,it can still kill you online)-saves battery,but is annoying at times

some have mouse+keyboard support.
dont think many do,though

cheaper, yes.
more practical,no.

wires are NEVER practical