Magento Multiple subscription periods

Hi there! What I need to achive is having recurring (simple) products with 4 recurring options: Month to Month (base subscription price 25$) 3 Months [+$50.00] 6 Months [+$125.00] Annual [+$275.00] Depending on the subscription period choosen, costumer will be billed for the same period when the first is ended. Like: Costumer buys 6 Months plan pays 150$ (25 + 125) After 6 months 150$ are billed again. Can anyone help? This is kind of urgent. Thanks