Tungsten Wedding Ring

My brother and I inherited an antique diamond engagment/wedding ring appraised at 14,000 dollars, I believe its a little over 3 carats. We were told that we were to sell it and use the money for college, however I cannot find any place where I think we can sell it for what it is valued at or even around what it is valued at. Any idea’s?
I tried ebay but it seems no one bids on really expensive rings, especially antique ones.

My brother is actually the one wanting advice. lol

My brother want to give her a gold ring, with an Emerald encrusted.
How much does an cost?
Cheap:
Normal:
Expensive:
Can a gold ring with an Emerald be actually used for a wedding ring?
My brother fiancee is dark like Beyoncee, will that combine?