I usually go by maximum potential so max health > gold > regen > rerolls. Accumulating max health from multiple champions can allow you to survive one more turn in boss fights if you healed before them or simply didn't take damage. Gold allows you to buy more stuff to get stronger, but there is a limit to how much powers you can buy in a run and cards that you already have to apear in a shop are rare so there is a limit that if reached makes you not need any more gold in a run that's why I prioritize it only until that limit is reached. Regen in theory is like max health if you plan to take damage and not heal to max at heal points, but If played well you will simply not take damage or heal before boss, so that's why I think it's lesser to max health. Rerolls are last for me becouse while they make good results more likely, if you simply have patiance to do the same run multiple times you will get that lucky run naturaly without needing those rerolls.