A quick look at McMaster-Carr shows a 12" length of 1-1/4 for about 35$. Do you know what you're getting? An assortment with a couple of pieces of 1-1/4 would make it a better deal than Mc-C.
I used to buy grab bags of electronics parts. Most never got used.
An assortment of brass probably would get used up in time. Could you be certain that a grab bag would satisfy the needs of your 100 piece-a-week project?
Weston Bye - Practitioner of the Electromechanical Arts - Author of The Mechatronist Column, Digital Machinist magazine