The decorative range legs can be bought from the Castle Wars lobby for 30 Castle Wars tickets. They can be bought from only Lanthus. It requires level 30 Ranged to wear.
Upon release, the Decorative range legs required 60 Castle wars tickets to purchase. This was reduced to 30 in an update on 11 May 2017. If a player bought one before this date, they can speak to Lanthus, found in the Castle Wars lobby, to reclaim 30 tickets.