When does the discount timer for how much time and how much res it costs to rez your hero start? When I read the wiki I understood it was from the moment hero dies the resurrection discount starts, but when my hero first died it had 80% discount right away. Does it start from the last time your hero became alive (or in case of new server, since the start of server) or is it just a start of the game bonus, first rez is always 80%?
The first death is a "freebie" where you get a big discount on the time and resources to help out the early game. Every death after that starts out at the max price listed here:
and gets cheaper the longer the hero stays dead.
You should always revive your hero immediately though as the amount of resources it produces more than make up for the higher resurrection cost + you can't do adventures or gain exp from robbers or participate in attacks or defenses very well without it.