DynamicPDF Converter for .NET offers a fully functional Evaluation Version. The evaluation edition never expires and contains the same complete feature-set as the purchased copy. However, when using the evaluation edition, printing a document will have a watermark on the printed page. Purchasing and applying the appropriate license key removes the watermark.
You can also download examples directly from GitHub (converter-dotnet-core). There are examples using both C# and VB.NET.