PvE Build/Set change?
What I would suggest is:
Experiment with different gear stats using exotic which you can get relatively cheap using the TP/karma/dungeon tokens/badges of honor. And, pick ascended gear stats that are most useful for doing stuff where it is most beneficial like high level fractals, raids, or for wvw if you are a hard core wvw’er.
You can change ascended weapon and armor stats in the mystic forge… the mats cost several gold per item, but still much cheaper than crafting a 2nd piece.
Accessory stats are mostly permanent. The only ones with changeable stats are the ones from Bloodstone Fen or the legendary backpieces. Most accessory costs can be offset through various means (WvW badges, guild commendations, fractal relics).