Discount/coupon In Store

We are creating our first store, and want to provide a discount for those who purchase multiple items, but not necessarily of the specific item. So, if someone spends $100, they get $10 off. 

If we create a coupon, won't that apply across all galleries? I can only find quantity discounts for quantities of the same item. And, I can't find a way to (in Store only) create a sale.

Any way to do this?

You would need to use a coupon for that. And the coupons could apply to gallery photos if they have the coupon code. Not a way to limit it to only store items.

Thanks, Tim.