Thanks to MyAddiction for the previous guide; special thanks to bodierox.

Directory:
I. What is price checking?
II. The marketplace method
III. Checking the item's history
IV. The Google method
V. Improving your price checking accuracy

I. What is price checking?
Q: What is price checking?
A: Price checking is the method of checking the current market and using past market knowledge to estimate the price of an item.

Q: I can't figure it out -- where can I get help?
A: You may post a price check topic in your respective core: Softcore or Hardcore.

II. The marketplace method
1. Open the marketplace in Ladder Slasher.
2. Select the following filters to search for similar items:
• The item type (Weapon/Armor/Charm/etc)
• The item class (sword/axe/plate mail/etc.)
• The item level
• The item's attributes.
You can reduce this by a few % to get more results to compare with. For example if an item has 110 ee you can search for a minimum of 100. Something else that can be done is search for a scale armor instead of a leather armor or a padded robe instead of a plain robe, etc. These type of items have very similar values most of the time.
3. Click search and take note of the prices

This method can be a bit unreliable at times since the marketplace can be empty and sometimes an item has been sitting on the marketplace for long periods of time which can mean it's priced too high. This is why you should supplement this method by checking the item's history and by using the Google method both of which are explained below.



III. Checking the item's history
This section will explain how to find what an item has been bought/sold for in the past.
1. Find the item on the person's account.
2. Right click over the item.
3. Select Inspect element.
4. Right click on the number right above the highlighted line that pops up and select Edit as HTML. This is the item's ID.
5. Select and copy the item ID.
6. Replace [ITEMID] with the item ID in the link below:



There are a few important things to keep in mind:
• If an item has never been bought or sold then it will obviously not have an item history.
• If an item is hidden in a vault then you won't be able to get the item's ID.
• If a user has their ladder slasher characters hidden there is still a way to see them. Simply go to their profile and copy the numbers (the user's ID) at the end of the link after i=. Then go to your ladder slasher characters and replace your user ID with theirs.
• The history doesn't always reflect what an item was bought/sold for; sometimes users sell bulk items and to facilitate the trade they simply divide the total price among the items or they also loan items to their friends and do so by transferring them through the marketplace for a low FG amount.
• It may have been a long time since an item has been sold and as a result the market value of that item may have changed.
• Lastly, the item history is just to be used as a reference and should not be used as the sole reason to value an item since it's not always an accurate way to gauge an item's price.

IV. The Google method
1. Go to Google.com
2. Search site:d2jsp.org "Ladder Slasher" "Item name" "Item Attribute" "First 1 or 2 digits, if it's Enhanced Effect, of the attribute." with the quotes included.
For example, If you want to price check a 164 EE MQ sword you can search: site:d2jsp.org "Ladder Slasher" "Ultimanium Sword" "16" "Enhanced Effect"
3. Go through the results. This may be a bit monotonous, but you're going to be able to gather a lot of useful data from previous trades and price checks.

Additional things you can do to the search:
• You can also add "2014" to find more recent topics.
• Add "Price check" to find previous price check topics.
• Add the exact attribute value of the item to also find previous trade or price check topics for the same item.
• Search for similar items instead, for example, search for fires instead of earths or plates instead of chains, etc.

So how will all of this help you price check an item? Well, by doing this you are not only able to get previous sale prices for items that were put up for 1 FG or for items hidden away in a vault, but you will also get how long an item was bid on, how many bidders, what the offers were, among other things. All of this information can prove to be extremely useful to consider to accurately price check an item.

V. Improving your price checking accuracy
There are a couple of things you can do to improve your price checking accuracy:
1. Take notice of what people are bidding on. Keep track of the offers and of the bids. If an item stops getting offers and the only activity in the topic are bumps then the item has most likely surpassed its value.
2. Keep an eye on what is on high demand. A good trader will always observe topics and see what is getting bid wars and if there are multiple ISOs for the same items. When price checking something simply tag it with "this is likely to get higher based on demand". Also advise them to not put a bin or short deadlines on the item.
3. Document trades. Keep a spreadsheet or a notepad document of prices or bids for specific items within a specific stat range and level to be able to quickly price check and compare similar items in the future.