"so the players would know the value instead of playing with pretty pieces of plastic"
Surely the players know the value anyway, they must have bought in to get them

John

Many roulette tables may have 25c minimums from 6am to 10am, $1 from 10am to 6pm, $5 to 6am.
What if someone wants to play $5 a chip at 8am etc. Think how many different chips would be needed. Roulette tables would have to be bigger