Depends on how much hassle you want.
As others have said, it's best to find out the melt value of the gold to get a sense of what that's worth. Then if you care to, you can shop it around to jewelers or pawn shops and see if they'll offer you more than the melt value, which they might not, or they may, but only on consignment, in which case you have to wait for someone with your husband's size and taste who is willing to buy a used wedding ring despite the stigma.
Jewelry is hard to sell. Thankfully gold rings are much higher percentage on resale than diamond rings, so that's a bonus. For most diamond rings you can only expect around 10-20%.