Hi Andrew,
The best options is to get a Visual Studio subscription. This includes VS + Platform Builder (all versions) + a LOT more. I think the price is close to just that of WEC2013 alone, and you can download everything straight away. I have the "Visual Studio Dev Essentials" subscription. Go here: https://visualstudio.microsoft.com/dev-essentials/
Hopefully that will take you to the right page to purchase. I can't see that anymore because it requires me to login and then it detects I already have the subscription, so I never get to the purchase site...