Enchanting is a huge gold sinker. However, I took it up at Level 38 (of all times) together with Tailoring after getting bored with Herbalism and Alchemy (plus, i was getting tired of paying high prices for my weapon enchants). Took me about 10 levels (38-48) to reach the level 225. At this point you have to go to Uldaman to meet the Master Enchanter to become an Artisan.
Once you've reached lvl 225, you'll be able to sell the 2 most popular enchants --> 2H +5dmg, and 1H +3dmg weapon enchants (both give blue glows), and it will become a huge wow gold-making profession. I sell them at 4g-5g per enchant and there'll always be somebody who needs it. At one stage, I earned almost 100g in just 3 days of selling mid-level enchants. I guess people should add this to those free
. I felt like a door-to-door salesman but it was fun, especially when you get a whisper from someone who wants to buy your enchants.
That's said, Enchanting is one of the toughest professions (heck, it's the only profession which requires you to go fight elite mobs at Uldaman to get your artisan) but it is also one of the most rewarding. Enchanting is easy to level especially if you're already Lvl 50+ and your finances are stable. If you're short of ingredients, simply make a quick run to Deadmines/SM/WC and other instances to get all your green/blue items. Auction Houses can either be your best friend or your worst enemy. Always keep a lookout on good deals. I've set up an excel spreadsheet to keep track of the prices of ingredients sold at AH. This allows me to identify good bargains and setting the prices of enchants.
The last important point is the number of enchanters in your servers. If you find that there are too many enchanters spamming their enchants on the trade channels at IF and Org, then you'll find that enchanting is going to be tough. Competition means competitive prices. Good for the customers, bad for business. Fortunately, enchanters normally keep their prices realistic and on par with the prices on AH. No one sells enchants for low prices just so that they can beat the other enchanter. And the people who buy your enchants are not stupid either so don't try to cheat them by overpricing your enchants. Otherwise, people will remember you as a bad sales person and will avoid you in the future.
Overall, enchanting is highly addictive once you've passed the 200 mark. No doubt, it burns your pocket during the early stages. But if you do lots of instances, are prudent with your spending, and spend time monitoring the market conditions at the capital cities and AH, then enchanting can be an enjoyable profession to take up. Otherwise, stick to disenchanting and you'll still be able to make a decent amount of money.