looking for any working g4 mac

[14yroldmacuser!]

Hey, 14 year old here looking for any G4 mac! No preference for specs, as long as it is working. I would like it for free or very cheap as I'm on a EXTREMELY tight budget. If i can get 2 of them that would be great! I need need one as i have never owned a mac with anything faster than a 400mhz g3 in it. The other one would be going to my grandfather. He currently is a winblows user using his Pentium 3 is dieing..... so wants to convert thanks to showing him my current mac! Everything would be appreciated! Thanks!

Matthew :{D