See RipOmeter (http://geekhack.org/showwiki.php?title=Island:6189) for Canadian nickel values. Depends on the year.
You'll need 70-90g of them. That sucker is stiff.
Me posting this got me banned at Deskthority.net for "threadcrapping". (http://deskthority.net/viewtopic.php?f=7&t=705&start=60)
Show Image
(http://i123.photobucket.com/albums/o293/z50r_bandit/pc%20photos/DSC05194.jpg)
Okay I'll drop a few on it later. It'll take a lot, though.
You can actually fatigue your hands incredibly well with a peerless. I wager the reason for the stiffness lies in the fact that the spring doesn't "buckle", so it's similar to the C64's awful keyboard.