Marketpress Coupons: $value off based on product

Here's the scenario:

We have a great Marketpress site that we'd like to offer a $ value coupon - say $15... on our high volume items.

At the moment I'm fairly certain (but I'd love to be corrected) that we can't apply a discount to individual products, or product categories which means it must apply to everything in the store. This causes us an issue because some of our products are high value, and some are low... so people could currently use the discount to get the low value products in the store for free.

The solution we'd like to see is:

Coupons that provide a % or dollar value off:
1) individual products (new feature request),
2) categories of products (new feature request); or
3) all products (existing)

Love Marketpress and where it's going...

Thanks,
James