You can always purchase the mats on AH or purchase items that will DE to the mats you need. Either way it's not going to be a cheap process.
Here's a guide on how to quickly level up your enchanting skill with minimal mats.
If you can't find the mats you need here's a chart showing what items DE into. Generally the dust is from armor and the essence is from weapons, though it can randomly be anything.
Level 01-10: A little strange dust/lesser magic essence.
Level 11-15: Much strange dust/greater magic essence.
Level 16-20: Much strange dust/lesser astral essence.
Level 21-25: Little soul dust/greater astral essence.
Level 26-30: Much soul dust/lesser mystic essence.
Level 31-35: Little vision dust/greater mystic essence.
Level 36-40: Much vision dust/lesser nether essence.
Level 41-45: Little dream dust/greater nether essence.
Level 46-50: Much dream dust/lesser eternal essence.
Level 51-55: Little illusion dust/greater eternal essence.
Level 56-60: Much illusion dust/greater eternal essence.
What is your other profession? You can help offset the cost of enchanting by picking up a gathering professions like mining or skinning. Also sell off whatever mats you no longer need to use to level to recoup a few extra silver.
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Azoth