There are many guides to Jeweler on the internet. Most of them require an excessive amount of crafting to complete. Below is an exact list of every material necessary to level Jeweler to 400 and the instructions for crafting. Do all crafting or discoveries in a step before advancing to the next step. In the left column, the prices that I was able to find and the costs for each step.
A quick note about the T5+ items: the crafted jewelry are expensive, but most, if not all, of the cost can be recovered by selling the jewelry on the trading post. I used opal below, but it is not necessarily the best option. Check what prices jewelry is being sold for on the trading post first and determine what gem will result in the most profit.
A word about terminology: gemstones are mined from ore nodes; jewels are created by combining a filigree with a gemstone. T1 means Tier1, which refers to crafting levels 0 – 75. See the following chart for tiers:

The charts below are available in an Excel Document that can be used to accurate track costs. All prices are in copper pieces. You can also view current prices using a live updating google spreadsheet created by a MassMediocrity.
For the T5+ (crafting level 375), you will need to buy the recipe of the Jewel from the Master Jeweler.
