Just found out about this "Catalog" feature that RO has and is already supported in rAthena.
It can open the store that's selling the item right then and there.
http://www.playragnarok.com/news/updatedetail.aspx?id=183
in the source they are outlined as
/// Search Store System
void clif_search_store_info_ack(struct map_session_data* sd);
void clif_search_store_info_failed(struct map_session_data* sd, unsigned char reason);
void clif_open_search_store_info(struct map_session_data* sd);
void clif_search_store_info_click_ack(struct map_session_data* sd, short x, short y);
in the script commands
*searchstores <uses>,<effect>;
Invokes the store search window, which allows to search for both vending
and buying stores. Parameter uses indicates, how many searches can be
started, before the window has to be reopened. Effect value affects,
what happens, when a result item is double-clicked and can be one of the
following:
0 = Shows the store's position on the mini-map and highlights the
shop sign with yellow color, when the store is on same map
as the invoking player.
1 = Directly opens the shop, regardless of distance.
Example:
// Item Universal_Catalog_Gold (10 uses, effect: open shop)
searchstores 10,1;