Taken from my BW guide I have a Section called 7a. leveling and powerspikes
viewtopic.php?f=75&t=35047
I will take out the ability names for you sine they are BW related. and hopefully it can give you an overview of when you can get new armor, weapons and accesories:
(M) is mastery abilities/tactic
(T) is tactic unlock
(A) is ability unlock
(i) for item unlock
Level 1: Starting abilities.(A)
Level 2: 25% starter dunkey mount (i)
Level 3:
Level 4:
Level 5:--------
Level 6:--------
Level 7:--------
Level 8: First tactic slot.
Level 9: Green accesory gear from vendors in Tier1 WC or capital.(i)
Level 10: CR10 RR10 scenario weapons(i)
Level 11:--------
Level 12:
Level 13: First green vendor shoulders with int.(i)
Level 14:--------
Level 15: orvr gear with int bonuses.(i)
Level 16: 2nd tactic slot + Int tactic(T). 8gold mount from in T2 Empire wc(i)
Level 17: First dungeon in capital for 3piece set(i)
Level 18: Green vendor accesories(i)
Level 19: Int + wounds green helmet from vendor(i)
Level 20: M2 Focused mind(A). New Scenario weapons(i)
Level 21:--------
Level 22:
Level 23: Green accesories from vendors(i).
Level 24: 3rd tactic slot(T) New scenario weapons(i)
Level 25:
Level 26: oRvR armor set with int. Green Cloacks from vendors(i).
Level 27: oRvR armor set with int(i).
Level 28: oRvR armor set with int. + critchance(i).
Level 29: New scenario weapons + oRvR armor set with int(i).
Level 30:
Level 31: Last level of lvl 48 bolster, next level you will be bolstered to lvl 40 only(!)
Level 32: 4th tactic slot(T).
Level 33: Green Accesories from vendors(i).
Level 34: New Scenario weapons(i).
Level 35: Scenario/orvr armor with int bonus(i).
Level 36: Gutslime weapons useable(i).
Level 37:
Level 38: 660 armor potions useable and +mainstat potions(i). 100g mount available(i). Green accesories from vendors(i).
Level 39: New scenario weapons(i)
Level 40:
The vendors are all gathered in the capitals in the same area. go check them out to keep your accesories up to date if you dont drop them from pve/player/bags

hope this helps (also dont mind the wording being focused on int instead of willpower)