It's spelled out clearly on the order page – there's no special upgrade pricing, unless you bought v4 on or before June 1st, 2017, in which case it's free.
Yes, thank you. That was not there PRIOR to Transmit 5, for the past 6+ months. I wanted to purchase it, and if I did in May, I'd be paying twice for 4 and 5 in a two month time frame.
