Just my 2 cents but DO NOT sell it to the jeweler. He's looking to buy wholesale from you and he'll turn around and sell that $550 ring for 2K minimum.
Jewelry markup is typically 400% give or take.
Get it appraised (Say 2K for argument's sake) and put it on Ebay or something for $1,000 and turn a better profit.
Just my two cents from having bought an engagement ring once and then having the store I bought it at offer me $1,000 (when the engagement ended, that you God) on the ring they sold to me for $4000. I sold it myself for $2500!