As a web developer and blogger I'm always looking for affordable photos and illustrations to use in CodeHill and the other websites I work on. I've been using these three stock photography websites for a while now, they provide good quality images for reasonable prices.
Stock Photo provides free and paid lifetime memberships. The paid membership costs $49 Dollars and provides 5% discount on any image downloaded.
Shutterstock provides on demand payment as well as membership based download. The on demand payment allows you to pay $49 for 12 downloads or $229 for 60 downloads. While the membership allows you 25 downloads a day and costs $249 for 1 month to $2559 a year.
iStockphoto is my favorite. The best resolution and size of images for the Web are their basic and detailed images and they cost $2 and $5 respectively. iStockphoto provides vector art, audio, flash and video too. Like Shutterstock registration is free and a membership based downloads for a monthly fee is available. One thing worth mentioning is illustrations cost 2 to 10 times the cost of images.
I found the best combination to save money without paying a monthly membership fee is to use on demand payment with iStockphoto and Shutterstock, but using the first for downloading images only and the latter for vectors and illustrations only.