25 cents
It depends on what state it was issued for, post new question
....25 cents just like any other post-1965 non-proof quarter. State quarters are not rare or valuable unless they are proof or have some error.
If you mean a 2005s proof California state quarter retail is $1.10
Unless the quarter is in mint-state or a proof, the value would be the melt value of the silver in the coin which is $3.80ish as of this time of writing, but changes depending on the spot price of silver.
A 1999-S Delaware Silver Proof Quarter, certified as a PR-70 Deep Cameo example has a listed retail value of $3,000.00.
1974 S (Proof) Quarter is worth $1.50.
Unless it's Proof, it's just a quarter.
Averge retail value is $2.00 for this coin.
If you found it in change, it's 25 cents. The retail value of a single proof is about a dollar.
A 1988 Proof Quarter is only work the face value, for the most part. To some collectors, they might be willing to pay as much as $18, but this is rare.
There aren't 112 proof state quarters. There are only 50 proof state quarters, (along with 6 in the DC/US territories). Unless you are meaning you had both the clad (copper-nickel, common) proofs and the silver proof sets. But just about every clad US proof state quarter is worth about $1 or so, silver proof quarters go for about $7-8 or about fifty cents or a dollar above melt value individually.
Retail price for a Deep Cameo Proof is $2.30