Disclaimer: I work for Chargify. While biased, I'd have to agree with (and thank!) the Chargify supporters below :)
Here is a great post from our blog to check out: https://www.chargify.com/blog/buy-vs-build-subscription-bill...
And an excerpt from that post:
Nick Sonnenberg, Co-Founder of Leverage, explained that “Chargify has a wide variety of capabilities you don’t know you need until you need them, such as dealing with expired credit cards by notifying the client automatically. It allows us to upgrade, downgrade, or cancel a client’s subscription easily. There’s a self-service page, which allows clients to update information on their own. It provides metrics month-over-month on critical data such as the number of customers, revenue, and lifetime client value.”
Looking back at their own experiences, Sonnenberg has this advice for new subscription-based startups: “Start with Stripe + Chargify. You’ll save time and money in the long run.”
Good luck in your quest. Let us know if we can help answer any questions for you!