product discounts on first purchase but not on renewal

Verzoek

I'm missing a possibility to offer a product with for example 40% discount at the first purchase which will be charged with the full price (100%) after a regular renewal. example: first purchase of a webhost package has: - monthly | 0% discount - half-year | 30% discount - one-year | 40% discount renewal the webhost package has: - monthly | 0% discount - half-year | 0% discount - one-year | 0% discount with the current possibilities, this isn't possible because the price doesn't change after renewal to 0% discount.