Managed services are usually costly. But if you've enough $$s, I'll choose managed services.
Even though I don't have enough $$s, I'm still using many managed services. The key advantage is "ship fast". As a startup, moreover reducing the price, I'd prefer to ship features fast.
While looking back at MFY we may have built 10 features with the help of many managed services. Out of 10, only 3 or 4 was very useful for customers. So we dropped the rest. If you didn't choose managed services, we may don't have enough time to ship all these 10!
What I would say is go with managed services first, once everything is up and running and you have a good team to focus on devops, gradually migrate away from managed!
In short
Pros:
Cons: