HP offer XL ink cartridges, which are much better value. Even within them, the different cartridges are different.
Number 350 - BEST. The black XL cartridge is rated for 900 to 1000 pages.
Number 300 - GOOD, though not as good as the 350.
Number 21/22 - POOR. Gonna cost you twice as much as the 350.
There is a standard test for ink lifetime. Some manufacturers, HP included, put the info online. (Annoyingly though, they use different numbers in the US compared to Europe, leading to a bit of uncertainty.)
I recently bought a Photosmart C4480. £40 from WHSmiths (who are still selling them), should be similar elsewhere. It's decent, though draft mode suffers from poor alignment and isn't really good enough for everyday use (unlike on my old HP Deksjet 3820). Haven't really tested photo printing much, though I did scan, enhance, and reprint a photo - some improvement, but original too bad to make it look good.
Kodak are marketing their printers on low ink costs. They were no go for me because they don't support Linux, but if that's not a consideration for you then maybe consider them. (Though you'll kick yourself if you ever DO decide to switch OSes)