It sounds like what you're asking for is a recurring billing product @Jerricka? If your store sales teas (as an example), you want Hearbal Tea for $19.99 but another product that is an Herbal Tea monthly subscription at $15.99 per month?
I'm constantly impressed by the value Websites + Marketing offers but as near as I can tell there is no recurring product option? Some plans do have a recurring appointment option, perhaps that can be used for your purpose? Recurring Appointments has a vast email reminder feature that could (referring to the earlier example) remind your customer that their monthly Herbal Tea is on the way?
Am I understanding your need properly?
...turns out that my two cents is worth less or more depending on the current exchange rate.
roy darling *my posts seem a lot shorter in my head