I had a conversation with admin of http://hk.rc-international.info/swarm/ to find out the cause:

• if the price for the current user is lower than price after discount, buddy-code won't work, what has sense. Usually platinum users can face this situation.
• and the second reason, if the code has been used six times (some sources say three times). It means each code has some eligible number of purchases it can autorise. Currently we are working on determination of the exact number.

Merchandise in the buddy-price catalogue started to have additional icon in the shape of cardboard box. This indicates weight in the package.
As an advantage you can search not only for specific items by names or characteristics but by the weight also. For example you are looking for something not heavier than 20gr. to fill the rest of your parcel. Just type in the search field «20 g» as a result of this request you will see all the merchandise not exceeding your 20 gramm limit.

On swarm list by default buddy-codes are presented in the chronological order.
 
Also we are glad to introduce our RSS-feed. Please have this option activated so you will be informed immediately.

Recently HobbyKing changed their policy regard buddy-codes.
 
HobbyKing does not permit to place more than two items with buddy-price in the basket.

There is statistical data on every web page of our buddy-codes catalogue. This data contains information about available buddy-codes, active users and the best sales.
 
A new option has been added that gives you opportunity to sort the merchandise by the amount of discount. So you can have a list of items that have the best deals from HobbyKing. 

Based on the growing assortment at all warehouses (US, AUS, DE, NL, UK) we decided to separate these warehouses in our catalogue.
 
Now you can choose the warehouse you prefer for shopping and search items in each warehouse separately.

Recently HobbyKing changed their policy and now customers can buy only one item that has buddy-price.

Now you can sort the merchandise on our web site by the price after savings and not only by the size of the discount.

Today HobbyKing announced new price for this item Polyquest 4950mAh 5S 25C Lipoly (Version 2). Regular price was $159 so it is on sale for three times cheaper than ever.

This can be related to the low stock levels that HobbyKing is trying to clear out. By the way there is no information about this item not in the Flash Sale not in the Sale/Liquidation categories.

This type of sales without announcements and notifications happens on the regular basis. We would like to know if you are interested to see these sales on our web site. We could create a separate category for unexpected price drops. 

HobbyKing had detailed information about stock status available for a long time. For example how many items are available or how many are sold if there are zero in stock. It could give you an idea how big the line up was.

Unfortunately two persons (first & second) decided to show off their knowledge  on Twitter and disclosed this information to the public.  As a result HobbyKing is hiding this information and the numbers that are available aren't precise enough. For example: less than 50 in stock or up to minus 20.

We are currently working on the solution.