I don't really understand the difference between Easy Money, Maximum Profit, Buy Bid & Sell Bid
After crafting an item in Guild Wars 2, you usually want to sell it for the best price and therefore will use the Trading Post and not sell it to a merchant.When you open your trading post window, you can see the list of buying offers and the list of selling offers.
If you want to sell an item, you can choose to do so immediately by selling it to the highest buying offer available, or you can place a selling offer and wait for someone to buy it.
It is exactly the same process when buying an item. You can buy it immediately at the lowest selling offer available, or you can place a buying offer and wait for someone to sell it to you.
If the price of selling immediately (tax deduced) a crafted item is higher than the price of buying all of its components, then you are guaranteed to make profit. This is what the Easy Money does.
The other techniques are all using buy or sell offers, or both. With those, you would make more money but you would need to be more patient to buy the components/and or sell the crafted items.
To try to make the most gold with crafting, you obviously have to try to buy the components at the lowest possible price (placing buying orders) and sell the crafted item at the highest possible price (placing selling offers). To see those best opportunities, just have a look at the Maximum Profit page.
The 2 last techniques are a mix of offers and buying or selling directly.
If you want to buy directly the components, craft now, and sell later, you should go to Sell Bid
On the contrary, if you prefer to make an offer (that you can cancel at a later stage if you change your mind) to receive the components at the lowest possible price and craft them when you'll receive them, then you should open Buy Bid
Don't forget to click on the

When finding the best way to sell my component, how can I select which recipes to use?
To select or unselect the recipes you want to take into account for the computation of the best use for your components,
How to know whether I am buying/selling directly or with an offer?
On the Easy Money, Maximum Profit, Buy Bid & Sell Bid pages, have a look at the very top of the page for details
On the Recipe Details pages, you can directly switch the buying/selling mode by clicking on the "X"

On the Ingredients Details pages, you can directly switch the buying/selling mode by clicking on the Directly or Offer button.

Profit Displayed
The profit displayed in each pages includes the Trading Post Taxes.If we are using a technique that includes offers (buying or selling), we always take the lowest existing selling offer, or the highest existing buying offer. When buying/selling in the game, we can of course adjust those amounts.
Technical Details
The website is using the Guild Wars 2 official API to update the price continuously. The price of each item is updated about every 2mn.The benefit displayed is taking into account the Trading Post taxes.
If we are using one technique that includes offers, we are always taking the lowest selling offer available and the highest buying offer available. When buying or selling, you can of course adjust these prices.
Should I close my eyes and buy the components?
Of course not, you have first to check if you can craft this item (profession, level required and do I have or can I discover the recipe).You also need to validate the price of the components and the crafted item, as the best opportunities never last long!
Also, if you are placing buying or selling offers, try to estimate if you have a chance to conclude a transaction.