I haven't got a lot of cash, but I do computers for a living (PCs) and I'd like to have a mac around just to play with. Maybe learn about networking them to windows computers, as well as generally learning to run one. What's the slowest one I should consider for getting a feel for how they work, and how much should I pay? I just want something at least roughly equivelent to a 500MHz PC, maybe a bit more, and also would like (it's not a must) one that will run Yellow Dog Linux, as well as mac os. Don't forget I don't have a fortune to spend on it. It'd also be nice if it was somewhat upgradeable, but I am not so sure thats possible, andyway what do you think?