The price is 50$ for the package without the code. Depending on demand a code inclusive version and pricing may become available. The payment is done through PayPal and if invoice is required will be sent by post. After payment, at the e-mail you have provided to Pay-Pal, you will receive a zip file containing the vsix file the sample application used for the demostration videos. Here you can find a more detailed description.
Also here you can ask your questions regarding using the extensions or report bugs or suggest modifications or additions.