How much should a good killswitch cost? And where can I find them (Besides Ebay).
I live in the UK, just so you know.

I got mine for like $3 or something. Just find an electronics place on the internet and search for them. Keep in mind that there are all different types of switching, so picking out the right switch may take a bit of searching.
A killswitch is just a simple switch, costs $3 in RadioShak or similar stores. Its nothing special thats guitar related only. Different types like a toggle style switch (on/off) or a push button style where you ground the signal when you press it. I got this diagram from UG I believe

2003 Music Man Axis Pacific Blue Burst
Seeing as I live in UK Radioshack doesn't help me much.

Sorry to bother everyone again with a question, but instead of drilling a hole into the guitar, can I just take out a tone pot?
Yes you can thats what I did and I'm sure those types of switches I showed you are available somewhere in the UK
2003 Music Man Axis Pacific Blue Burst