I don't tend to buy the fresh stuff either -- too expensive. You can get liquid stock that lasts weeks after the bottle has been opened. I can't remember the brand name off hand, but it is very good. I have occasionally made my own, but the tiny kitchen near my college room isn't up to that kind of thing, really!

Ah, being in college is a good reason for taking cooking shortcuts! Not encountered the 'liquid stock in a bottle' thing though.