Where do you all buy cartridges?

Hey everyone

Anyone have a handle on how to update your printer software on a mac?

I haven't been able to print for the last few days and it is fairly important that it works in relation to my work.

In addition, I am very curious about where you buy your ink for an Epson printer? Preferably the cheapest.

I usually buy ink down here at the nearest bookstore, but I feel I can get the cartridges cheaper online.

I have looked at inkpro , has anyone had good experience with them?

Thanks in advance