I highly recommend the Canon Pixma all-in-ones - my own model is a MP610, I think they have now been superceded though. Don't get a printer that is _too_ cheap; with printers, you get what you pay for, and with cheap models, the colour reproduction and resolution is hideous. On my Canon, the print quality is superb - A4-sized photos look great.
Cartridges aren't that dear if you buy online; I was able to buy the cartridges for Canon for €5 online from Ireland.