To buy photos, select your gallery, click on 'Buy Photos" and then select "Buy Gallery Download".
If you have already purchased your photos, some people may have a problem downloading the images so I created a how to video.
You should be able to download individual photos and all the photos in bulk.
And FYI, you may want to skip ahead to about the 50 second marker to start at gallery download help.
Here is video on "How to Download Your Photos".