Profit from limited supply items

You all probably know how there are suppliers for all professions. Some of these get limited supply items every once in a while. Say for engineering they sometimes sell Bronze Tubes and Gyrochronatoms. You can buy them for 8s/30s respectively. But if you put these on the AH you can make a lot of profit! Mainly because people need them for quests and want to buy them instantly.

I myself was able to sell Bronze Tubes for 40-50s each (depends on the market, these tend to go for less sometimes because there is a lot of them needed).
The Gyrochronatoms can sell for a far higher price. I managed to sell these for up to 6g/each and I think you can probably ask a lot more for them because it's needed in the badlands quest for the trinket. If there is one on for say 90s bid only, you will still sell it because they don't feel like waiting ages.

Again, on older realms there might be a lot of Bronze Tubes/Gyrochronatoms but especially on new ones where the demand is quite high (a lot of people have to do that quest) and the supply low (Not that many people have engineering THAT high because it sucks up all your money..)

I myself already have 115g on a new realm. About 50g is from selling these items. Same thing applies to Limited Supply patterns etc. My character is L33 and I already have more than enough for my mount at L40. Combine this with skinning/herbalism/mining and you can make loads of gold!

As a last thing I've also asked quite a few people if they checked the supply vendors without having that specific profession them self and all of them said no. Why would they if they don't have the profession? Because of this you can go and check the vendors in the towns and buy the limited supply items! As an alliance I usually check the vendors in Stormwind/Ironforge/Duskwood for the limited supply items.

Hope you can make some gold with this tip! And don't spam the AH with them or you'll make the items worth less!

Good items to sell:

Philosophers stone recipe and the transmute mithril to arcanite recipes

Goblin Jumper Cables schematic

And many many more!