100-300 USD
Take it to a gunsmith. You did not say what is wrong with it.
100-400 USD or so
100-400 USD or so depending on specifics
if you mean the air soft pistol then yes it can take both 0.12 and 0.43 plastic bb's
Moondog Industries gas fill O-rings from evike.com. Quick, easy, and inexpensive.
neither, also it doesn't matter which one is "stronger", if you have a a high FPS (strong), you can't play on fields
First off, it's "picatinny" rail. Secondly, no there are no aftermarket rails for that model that I am aware of. However, a competent gunsmith may be able to machine the frame to act as such.
It depends on if you are getting robbed or not. In this, or a myriad of other circumstances it could be invaluable; so, if you see one in excellent shape for under $200 you should snatch it up. Sadly, as of 2005, this pistol was discontinued by Ruger and replaced with the current P345. They are getting more difficult to find, but as they are so durable they will pop up occasionally on the used market for $300-$400. You don't need a wiki for this, just use google products: http://www.google.com/products?q=P97DC
There are 10 distinct planes. Each point p1, p2, p3, p4, p5 determines 10 lines: m12, m13, m14, m15, m23, m24, m25, m34,m35, m45 and, therefore 10 planes: p123, p124, p125, p134, p135, p145, p234, p235, p245, p345