You can access the Shop Search either by a button on the minimap or by pressing F11. The Search covers both Kingdoms and works only on the same CH.
You need to type at least 4 characters to get some results.
As the tooltip tells you, you can either buy it or if you want to see what other items the shop might have you can set a target to locate the shop. You can also click on the mailbox to open a private message with the owner of the shop. You can choose to order the items by price too.
The star icon adds to your bookmark your favorite searches so that you don't have to type them all the times.
The buy function only works on offline shops, while the target info works on both. The system will tell you also the coordinates of the shops in case you have troubles locating it with the map.
It will also tell you if the shop is on another map
Added on the minimap a Target for the Metins.
You can use the letter "K" to add 3 zeros. You can now sell items the way you speak, for 1kk or 1kkk or 1kkkk.