Is this the Brunswick Balke Collender 3-ball ivory billiard ball set you had? It comes with a wooden box case.
They were made from soft Zanzibar Ivory, and came in 2" size and 2 3/8" size.
If this is the set you are talking about, they sell for between $500 and $1600 depending on the condition of the balls and the box.
This set went at auction for $500 but was valued at close to $1000.
Also remember that there are lots of them around... which drives the price down somewhat.
This one is in very good shape, was going for $1500.
In 2008, this set sold for $250.
Three Boxed Ivory Billiard/Pocket Balls, in a Brunswick-Balke-Collender Co. wooden box with label.
Provenance: Purportedly owned by Willie Hoppe (1887-1959).
And this guy had three of them, selling each for around $450.