$50.00 will get you 5 images at ShutterStock.com. They have a great library of high quality images. I had a need for images when I revamped WebsitesABQ.com recently. The second great image source is https://pixabay.com and their entire library is free. You can find a lot at PixaBay.com that comes close to what you'll find at ShutterStock for quality and selection. I've wandered away from the likes of iStockPhoto.com because of what seems to me to be price gouging.
So that's my list: