We've seen value in using the solution. It is worth the money. 

The ROI of Amazon API Gateway depends on the type of API being deployed. If you are monetizing your API, then the calculation is different. However, if you are using the API gateway for your own business services, you should consider the ROI in terms of the cost of developing a similar service on your own. This way, you can determine if the investment in the API gateway is worth it. If the cost of developing the service on your own is higher than the cost of using the API gateway, then the ROI will be great.

I believe the return on investment for API Gateway is satisfactory.

The solution is worth the money.

We have seen ROI. It's pay-per-use, so you won't lose any money.

We've not yet directly seen any ROI, but we weren't expecting to.