hmm, you sure pick the curly ones
I'll have a look at it - as usual, there are several ways of doing it
- universal storewide, the whole site, the simplest
- applied on an individual store and sub-store basis
- applied on a main store basis and automatically applied to all sub-stores
- applied on a product basis but made easier by adding a discount column to the admin page which lists all products
- add the coupon system I've been meaning to introduce - that way you can have a coupon which can be targeted at any product(s) or storewide
The coupon system I have had on my Resources module, for years now, can be applied as a percentage or fixed dollar amount, and is then applied storewide (by not checkling) or to individual product(s) (by checking) from a full listing of all products.
In the case of the Resources module, I apply the discount at checkout, provided I have enabled the global option of allowing the coupons. From an administrative pov, it can be a lot easier to promote with coupons. Storez would also need a coupon summary on the main page where you could choose to list, or not, coupons (some coupons you may prefer to keep private e.g. gift cards).
Whichever way it goes, there is considerable work