Zen Cart Bundle building tools allow you to build groups of products to purchase together, optionally at a discount. Cross Selling is a proven way to "build the basket" and get your customers to buy more of your products.
Zen Cart Bundles
The Discount Chooser Mega Module allows you to flexibly create product based (rather than dollars spent based) discounts with a built in admin panel....
$60.00... more info
Extended Family allows you to easily configure cross sells from an admin panel without the need for additional discounting. Cross sell items...
$25.00... more info