[JonathonW]

VS Professional is not discontinued: https://www.visualstudio.com/products/how-to-buy-vs

You can buy both it and Enterprise online. Not sure why Xamarin says to contact them for a quote, except that Xamarin's sales people really like to talk to people.

[iolothebard]

It's free in your MSDN if you're subscribed. I downloaded them all :-)

So if you're a VS user already, it's likely bundled with an MSDN subscription. Just link it to your Xamarin account and you're done.