I need to buy new printer ink.. at least I THINK I do.

Maybe you guys can help me.. I spent many hours with my evil printer.. reinstalled the drivers, downloaded new ones, checked for jams, checked wires, etc. but nothing works..

It's an HP and only about 1 year old, and rarely used. Basically it turns on fine, but whenever I try to print something, it takes FOREVER first to start, then it literally prints one line, takes about 3 minutes, then prints the second line.. continues on and on..

I don't think it's a problem with spooling. The ONLY thing I can think of is that the printer cartridges are either empty (even though they aren't) or somehow the heads got clogged or broken or something and it's malfunctioning.. when I let it try to print for 45 minutes or so, the end result is a page with very faint and crappy inkage.. so do you guys think it's an ink problem? I just want to know so I can just go out and buy more and fix it..

Thanks in advance!