With Phase 5 the balance between engineering specializations will change. Gnomish engineers get the Gadgetzan teleport trinket which will be incredibly useful. So far Goblin Engineering has been most useful with the winterspring teleport for Songflowers and Sapper Charges. As such we may see more Alliance players re-leveling engineering. For Horde it is much easier to get to Silithus so the effect will be less.
Why do we care?
Obviously we care because they will be buying materials to re-level their profession. If any of these materials are rare, or needed in the war effort they could see a short term price increase. I don’t think this effect will be particularly large, but you should be aware of it if you do anything like boosting, low level farming or end up with left over materials. They will likely sell slightly better for a while.
In addition any re-levelers may want to re-unlock some recipes they have lost. As such there may be more gold in engineering recipes for a little while as players look to re-equip themselves.
If we look at the material list in the wowhead 1-300 guide there really aren’t too many obvious candidates. There are several materials also used in the war effort, but none of them are needed in huge amounts. The biggest one is Thorium Bar, and silk cloth for alliance alongside Copper bars and Runecloth for both sides.
Runecloth has increased significantly in price since March, whereas Thorium bars has been on a more variable trend.
There are a couple of good BoE recipes for engineering that players will want to re-acquire. The most important one for me personally will be the Sniper Scope, which has sold really well for me. Thorium Shells are also a BoE world rop recipe that is very useful. The rest of the recipes are mostly vendor sold and thus less interesting, although if you want to vendor flip them you should see more business for a while. Check out my vendor recipe group for that.
Sapper charges can only be crafted by Goblin Engineers and may end up seeing a boost on alliance. With fewer crafters we should see higher profit margins. I’m personally leveling a profession alt specifically just for sapper charges cause it is so good.
This is on the speculative side
All of this is on the speculative side, and you are probably better off focusing on crafting for logistics badges, getting the new p5 recipes and crafting consumables for AQ if you want to make serious gold. This is more a side-show that might see some swings and might not be anything. Either way you should at least be aware of it.