A membership module, where customers can deside if they want a cheap product and become a member of the shop, or pay full price for the product.
Store owner will have the posibilety to set a montly fee for members.
Store owner can set max number of products that are allowed pr. customer pr. month.(Like: only 1 of each product in store pr. month for a member. if customers want two of the same product, then one product will be full price)
Something like this store: https://www.luxplus.co.uk
If you can dewelop this module, i would like to donate some money for this.