I do not plan on holding your hand all the way through the process. I expect you to know the basics of trading on the market place such as having a vending license. Hopefully you already know how to crawl and this information will get you walking on your way to having the items you want without begging for it. I suggest you have 1.5k-3k before you try to do this program. You need money to make money and this will provide you with a nice starting point.
One of the keys of being successful in any business environment is to know your products and your consumers. Product knowledge will be the key to making money in the market place. More specifically it is
crucial that you know the going market rates for items you plan on buying and selling. The
KEY is to buy low and sell high. Sounds simple enough right? Well it is and it isn’t. The problem is that the law of supply and demand has the market prices fluctuating constantly.
There are several ways you can obtain this price information. Personally I find just looking up the product in the market place is the best way to find this information. Be sure to sort the product by “Lowest buy price” so you may see what the lowest buy it now prices.

As you can see it lists the items by the lowest buy it now price. This information should let you know the relative market value of an item you plan on selling.
Now that you know how much the lowest buy it now price is listed as you know the least amount of money you should make for the item. I suggest you keep track of how much you paid for an item. Also NEVER pay more than the lowest market price for an item. The important thing to consider is your profit margin when selling your items. Ideally you want to make as much as possible 100% or double your money on every sell would be great. Unfortunately it doesn't work that way. Generally you're going to make 5-10% profit margins on each sale. In other words if you pay 1000 for an item and sell it for 1100. You will have made 100g profit which is a 10% profit margin (100/1000 ... Profit divided by purchase price). While 100 gold may not seem like much, do this 100 times you will have made 10,000g. Still think this is a small amount?
Don't be discouraged if you aren't making alot of money at first. It takes time to build a proper bankroll. It's important that you do not spend your profits on the items you want until you reach a reasonable goal. What's reasonable you ask? Well that depends entirely on you. I set mine to 50k before I start "donating" some of my profit to outfitting my character. One thing to keep in mind is that the higher price items will bring you more gold per transaction than lower priced items.
When I first started I bought alot of the following items: Mimzy, Syaoran's Cloak, Soot mask explode, lucky star, and Mokona hat. These are nice low priced items that are constantly on the move (being bought and sold). Its important to start with items that move fast since the more transactions you have, the more money you make. You want to try to buy these items at a sub 250g price. Though the price has fluctuated a bit, they seem to sit comfortable at 300 (this applies to the cloak, soot, and mimzy). SO if you can find a cloak for 200, you can probably sell it for roughly 300. You would have 50% return on your investment. The market prices do fluctuate 20-80g in either direction but over the last week it's been relatively stable.