Shoulders: Try and craft for some with better EHP stats (and maybe even more int)
Head: Consider either getting one with more crit or more vitality (these are quite expensive though in both cases)
Neck: Get a tal'rasha with 9%+ crit chance, great dps increase, and also if possible make it 6% elemental dmg instead of 5
Hands: get 8%+ crit on gloves, either through craft or buy
Ring: Your zuni pox should have crit chance on it aswell (these are quite expensive)
Ring 2: Your Unity should have crit dmg on it or atleast attack speed (depending on build attack speed might not be worth having!)
Weapon: Consider rolling a black dmg weapon (no elemental dmg) as your zuni's boots and tal neck will benefit more towards a black dps weapon.
Legs: Personally i would, if you wanna keep lacuni prowlers, go for rare legs with high int, AR and vit and 2 sockets
Basicly you have lots and lots of items to upgrade, i don't know how much of it is possible within your budget but atleast 1 or 2 should be doable (the Tal rasha neck would be a huge upgrade) and some of the items you can craft your way to.