TMZ broke the story ... several jewelers claim the market value of the necklace is anywhere between $800 and $1,000. Under California law, if the item in question is worth $950 or less, the case must be filed as a misdemeanor, not a felony.
Deputy D.A. Danette Meyers tells TMZ, "If Shawn (Lindsay's lawyer) presents me with credible evidence of value, we will take a look at it. But based upon what's in front of us -- what the store owner and designer said -- the necklace is worth $2,500."
Meyers adds, ultimately "It's a battle for the jury."