Collecting the nobles deck is the method to get your diamond car greatness and WoTLK Gold buyers will be paying huge amounts of money for it. So even a single card will sell for 1000s of gold. If you have lady luck on your side and are able to cast some noble cards at a time and you'll absolutely roll in it. If you're patient and want to trade some cards with friends to make an assortment of cards, you're sure be sorting through gold for a good amount of time.
Engineering hasn't been a field that are known for their gold-bearing potential, and for its respect in Wrath of the Lich King. This doesn't change too much. There are many methods of making gold they're not likely to be the most effective. In fact, I'd likely say that it's pretty similar to not quite the most terrible, but getting exalted with either the Alliance Vanguard or horde expedition to have the mount in the Macondo hog in the Horde and the Chopper so that the alliance could be on the move.
However, as you can observe they are so heavy that they are quite a grind to be in a position to sell and make it . It's not really part of the normal and stable gold-based incomes we're hoping for from each profession. Instead, we'll be looking at items like the Sapper charges that do not require a lot in terms of mats. However, the majority of, engineers will be using these for raids, and you're hoping they're not inefficient or lack access to mining equipment to create them their self instead they'll purchase them from the Auction House.
This is also true for the saronite bombs. You can make massive quantities of by creating boxes of bombs and selling the saronite bombs on the Auction House. Also, you can create arrows or ammo which hunters will purchase frequently from auction houses It's likely that the amount of gold you'll be able to buy WoTLK Classic Gold make will not be huge, but definitely should be regular. If you're hunting you'll be looking at items such as the Heartseeker scopes.