I have addon-manager
Do not see anywhere inside Fsx to pay for this
If you have the Addon Manager, it's just not possible you don't see where to pay...when you select the Addon Manager, there's a list of publishers on the left (select Fsdreateam) and a list of products on the right (select Las Vegas). Then, select the "Buy" button to purchase from flight sim, or select the "But on Web" to purchase with the browser, which is required if you want to pay with PayPal.
It was all explained on the installation guide, named fsdt_install_guide.pdf, to be found under the fsdreamteam folder under your main FSX folder, after installing the Trial
