Hey there! I am currently very, very low on gold. I had stacked around 300+ stacks of Pyrite Ore (Spent a total of ~11k) but I later on found out that you will not get epic gems out of prospecting them. I now have the following:
Alacite = 265
Zephyrite = 233
Hessonite = 284
Nightstone = 217
Jasper = 240
Carnelian = 0 (made spikes with it and got Greater Celestial essences)
I've heard of the Obsidium/Elementium shuffle but Hypnotic Dust sells for 80s each on my server. Even if I make other JC items with the uncommon gems I will be unable to return the gold I lost there. Rare gems are also stupidly low. I have 3 85s with the following professions:
Wait till 4.3 hits before selling your cut rare gems. The demand and price for those blue buggers will skyrocket with the upcoming patch because we've been given a lot of new loot tables from the LFR, the three new heroic dungeons, the Dragon Soul raid and the new PvP season.
If you can find out which JC daily is up, some of the uncommon gems sell for way more than they really should on the days which they are demanded.
If you are the farming type, I would spend some time farming herbs and store them for the launch of 4.3, and also cloth (TB is a great place for this).
Unfortunately you will probably not get your money "back", it just isn't the way of the economy. You will just have to work a little harder to get yourself back up to where you want to be.