I used this method on molten-wow for 3weeks got over 60k gold on frostwolf realm and they've fixed it. It might work on your server, when done right
it's 3500g/hr pretty effective. also you get infinite amout of saronite ores,rare/uncommon quality gems also eternal earth and shadow. good way to boost your jc and its best effective when done with a druid/rogue due to stealth ability.
so here's what you need to do:
1) make a raid group and enter ulduar (it doesn't matter 10 or 25 u can go both)
2) inside of ulduar in entrance add a teleport location so you can leave fast. (for lazy people "ULDUAR giris" in the image is the entrance location.
3) teleport one of the locations ULDUAR VEZAX MADEN or ULDUAR VEZAX MADEN1, locations can be seen in image below.
4) it maybe not exist on your server but there should be 2 pure saronite ore which drops all of the below.
also it didin't required any mining skill in molten-wow but it maybe requiring 450mining on your realm also.
5)loot the nodes than teleport back to entrance.
6)reset instance
7)rinse and repeat.
by vendoring everything i was able to get 700g per 5 mins. If you're too lazy to farm and your server has an active auction house you might want to AH them.
So here's my advice on that:
download 2 addons: Auctionator and Enchantedstacksplit
enchanted stack split helps you a lot when you want to put those gems in ah 1by1 (some private servers gets bugged when it tries to autosplitstacks this is why i recommend using this addon) and auctionator to see/scale the price that you should add.
i hope this method works for you well