Dear Client- There's a relevant amount of knowledge dealing with Avangate API that helps to manage subscriptions & customers, Create/update or extract product catalog and pricing information in account and many more things.
And as I have 5+ years of experience in C#, ASP.NET, ASP.NET MVC 3-5, HTML/CSS, SQL, JavaScript and Payment Gateway Integration So can definitely integrate it in your .NET C# project, but still I need to once review your Web App so provide me the same before we commenced ahead.
For more you can check my profile reviews that depicts you my quality work. Thanks.