Just out of curiosity, some questions:

What's the rendering power you have available? I ask this because from the customer's perspective, it's completely different to pay $10 for a render you deliver in 5 minutes or a render you deliver in 5 hours or 5 days. I might be willing to pay $10 for a 5 minutes result but for sure not willing to pay the same $10 for a 5 days result.

Speaking of deliver the render result, is this service automated in your side? I ask this because if it's not automated, then the timezone you're on is a problem (you're sleeping when your customer is expecting their render results and vice-versa).

What about Cornucopia protected content? Do you have an agreement with them? If not, you will not be able to render scenes with this content, unless you bought it yourself.

How are the files exchanged with your service? Many scene files have hundreds of MB and if your bandwidth is not very high, this will take a very long time.

What version of Vue do you have? If you have any less than 6.6 Infinite, then this will bring heavy restrictions on the scenes that you can render.