Spiders
Just point one of these at a site, and you'll get everything. My favorite is TeleportPro.

TeleportPro	Lots of features. Evaluation doesn't expire but is limited to 500 downloads at once: plenty.
DownThemAll	FireFox extension. Run this one from the imagelist where you can see all the names.
HTTrack	Step-by-step wizard
wget (Homepage)	No installation needed, a commandline prog run from a bat file. Ctrl-c it when it's got the images.
WebZip	More GUI

Tutorial

Install TeleportPro.
In your browser, pick a game on the left.
    Save the renamer of an expansion (far right column is the best source).
    We'll get back to the renamer in a bit...
    Right-click the imagelist link to copy its address.
Start Teleport, and go to Project-NewStartingAddress.
    Paste the address into StartingAddress.
    Check "URLs on the starting server or within the path of links to other servers" and hit OK.
Go to Project-ProjectProperties, Exploration and change the number of threads to 2.
Click the play button.
It will ask where to save the project. A folder will be created there with the images.
After the transfers finish, hit the play button again in case it missed a few.
You're done with the spider, close it.

Extract the renamer to where the images are, and run it.
The spider will have downloaded a copy of the imagelist too. Delete that.
Make a folder in ArcanistCCG/cards/GameName with the name of the expansion as it appears on this site.
Move the images into ArcanistCCG/cards/GameName/ExpansionName/


Repeat for each expansion you want. No need to get them all if you only play with recent cards.