umm can does anyone know the cost of the caps to close the valves from the bottom for a long and mcquade or a average price for one, i lost one at school

You`ll probably have to check with an instrument repair shop about replacement and price. If you don`t have one locally available I can recommend Caldwell Music Company instrument repair shop in Abilene, TX. You can contact them by phone at 325-695-7382. They recently performed a complete restoral on the cornet I started learning on 50 years ago, and their work is excellent. If they carry replacement caps for your brand of horn, I imagine they could mail one to you in short order.

By the way, the surest way to keep from losing those caps is:

A. Check them for tightness before and after every playing session.

B. Never remove them except when giving your instrument a thorough cleaning and flushing (recommended to be done monthly).