You probably are refering to Cinelli Pista curved (no brake handle) bars used in track or criterium races. Raddoneur bars are used for mostly road races or criteriums and allow brake handles to be mounted. These can be found on ebay for $30 to $80, depending on the season and style. Track bars can be found in two main types: steel (more strength and durable) or alloy (less weight).
However, ***you should know in advance what width size bars you need (e.g. 58cm, 60cm, 62cm, or 64cm) and what diameter size stem you currently have***. Nitto and Cinelli Pista bars are uniquely different diameter sizes!
Regards, Steve