We tested and like this service.  Especially with cost of other stock images today at istockphoto.

Here’s how it works,

Fotolia is the first worldwide social marketplace for royalty free stock images, allowing individuals and professionals to legally buy and share stock images and illustrations.Fotolia offers the largest image bank of free and affordable royalty free photos and illustrations perfect for any medium, web or print.Photographers and designers constantly update Fotolia with thousands of new photos and illustrations each day, while photographers and designers receive commission from each photo sold and revenue from advertising on the free section.

Credits are Fotolias form of currency. Credits are used to buy images on the website. Credit from $0.75Image prices are given in credits; the price depends on the size and use of the purchased image.

Fotolia subscriptions allow you to download between 25 and 250 images a day during the period of your subscription.Images downloaded using the subscription system are equal to the L size 4MP. The subscriptions are offered from:

via Fotolia Stock Images.