Season 4 is almost here, while its still unknown exactly when it will start, its no more than couple weeks away. Since today I decided to get my enchant mats for new gear before prices will sky rocket, ill share with you.
Here are exact numbers so you can get ready as well.
First of all head, legs and shoulders. While you can get head enchant any time for 85g and tomes/armaments around 10g on AH, you might want to pick up [Nethercobra Leg Armor]. Right now its around 500g on my server, used to be 300g before Island dailies destroyed economy. It will be much more expensive after s4 comes out. Also make sure to pick up meta gem of your choice. Also seems that surefooted will no longer be needed, with s4 gear you will have 85 hit without any gems/enchants. So i will switch to 12% crit , 5% snare + boar speed. That will trade 24 ap for 12crit , which is fair trade, and adds +9 sta on top of that insdead of +10 hit rating that now its obsolete and unnecessary.

As for other enchants.

Chest:
[Enchant Chest - Exceptional Stats] or [Enchant Chest - Major Resilience] 4x Large Prismatic Shard, 4x Arcane Dust, 4x Greater Planar Essence or 4x Greater Planar Essence and 10 Arcane Dust

Bracers:
[Enchant Bracer - Brawn] 6 xArcane Dust

Gloves:
[Enchant Gloves - Major Strength] 12x Arcane Dust and 1x Greater Planar Essence

Boots:
[Enchant Boots - Boar's Speed] 8x Large Prismatic Shard and 8x Primal Earth

Ring:
1x [Enchant Ring - Stats] 2x Large Prismatic Shard, 2x Void Crystal

Weapon:
[Executioner] 6x Void Crystal, 10x Large Prismatic Shard, 6x Greater Planar Essence, 30x Arcane Dust and 3x Elixir of Major Strength

So for +6 all stats on chest, total is :
6x [Void Crystal]
22x [Large Prismatic Shard]
11x [Greater Planar Essence]
52x [Arcane Dust]
8x [Primal Earth]
3x [Elixir of Major Strength]

While for those who picked resilience on chest:
6x [Void Crystal]
18x [Large Prismatic Shard]
11x [Greater Planar Essence]
58x [Arcane Dust]
8x [Primal Earth]
3x [Elixir of Major Strength]

and on top of that total for enchanters:
2x [Large Prismatic Shard] and 2x [Void Crystal]

UPDATED:
If you have some spare cash, you might want to get more Void Cristals since those will be much more expensive in s4 (shatter Void Cristal cooldown removed) and you can make some cash on that easly.
(thanks for pointing that out Ano)

SandMan