Dimensions packs with big discounts at the Lego Shop: https://shop.lego.com/en-AU/Sales-And-Deals-Sets
Only a few variations:
$6.24 Fun packs - Sensei Wu, Aquaman, Cyberman, Bane, Superman
$9.99 Team pack - Joker and Harley Quinn
$12.49 Level pack - Ghostbusters