on test server/ru server, i seen several people with lvl 5 runes, pat 4 and wraiths.
Bear in mind that it is possible to transfer characters from the Russian servers to the test server with all their Boutique items. Also, there was a free item on the test server that granted instant level 60 and full 5 runes.
As for the exchange, yes it will go up, but that will be in proportion to the amount of gold the game gives. It will surge at the beginning of the patch because quests up to level 65 give a ton of gold, around 20-30k if I remember right, however it will settle down after a couple of weeks. As we will be 5 levels higher, symbols of gold will give more gold, and the amount of gold from traderoute, caravan, anomalous region, etherium etc etc etc have all been increased too.